Heads up: buy through a link here and we earn a commission from Amazon, at no extra cost to you. It never changes which product we rank first — how that works.
The short answer
DEWALT ToughSystem 2.0 is the best modular tool box system on published numbers: 123 lb on the DS400 large box, IP65 sealed, with auto-connect side latches that clip a box to the one below one-handed. Milwaukee PACKOUT is the better rolling chassis, publishing 250 lb for a whole stack on 9 in. wheels with every wear part available separately. The systems do not interlock, so the first box you buy decides the next decade of purchases.
The highest published single-box capacity here at 123 lb, IP65 sealed, with auto-connect latches that beat anything Milwaukee does — and usually cheaper than the PACKOUT equivalent.
The chassis the rest of a PACKOUT stack sits on: 250 lb published for the whole tower, 9 in. wheels that clear a threshold, and every wear part available separately.
#ad · Prices come live from Amazon, last checked October 10, 2026, and vanish from this page rather than go stale. Scores are ours, compiled from published specs and warranty terms — not from testing we did not do. Tap a row for the full write-up.
The decision is the system, not the box
Every box on this page stacks only onto boxes from its own family. The footprints differ, the latches differ, and nothing crosses over. That means the choice you are actually making is not which box to buy now but which ecosystem to be inside for as long as you own tools.
Which makes the right question narrow: what is the one thing you need the system to do that the others do badly?
Highest published single-box capacity, sealed — DEWALT ToughSystem 2.0. 123 lb on the DS400, IP65, and auto-connect latches.
A rolling base for a tall loaded stack — Milwaukee PACKOUT. 250 lb published for the whole stack, 9 in. wheels, rebuildable.
Drawers you reach without unstacking — Klein MODbox. Full-extension ball-bearing slides in a portable box.
Crossing rough ground often — Craftsman VERSASTACK XL. 7 in. wheels on a 33.9 lb four-piece tower.
The lowest possible entry price — Keter Stack N Roll. 7 in. wheels and a metal telescopic handle, no published capacities.
The published numbers, side by side
Capacity and sealing exactly as each maker publishes them. Two of the five systems publish no capacity figure for any unit, which is itself the finding.
Box
System
Published capacity
Sealing
Empty weight
DEWALT DS400 Large
ToughSystem 2.0
123 lb
IP65
Not published
Milwaukee PACKOUT Rolling
PACKOUT
250 lb total stack
IP65
Not published
Milwaukee PACKOUT Large
PACKOUT
100 lb
IP65
12.2 lb
Klein 54890MB MODbox
MODbox
Not published
Not published
51.3 lb
Craftsman VERSASTACK XL
VERSASTACK
Not published
Dust and water tested
33.9 lb
Keter Stack N Roll
Stack N Roll
Not published
Not published
Not published
Scroll the table sideways on a narrow screen.
Two things fall out of that table. First, DEWALT's 123 lb is the highest published single-box figure here and the DS400 usually costs less than Milwaukee's 100 lb Large box. Second, only Milwaukee publishes a figure for a whole stack, which is the number that actually decides whether a tower of four boxes is a good idea.
Why the latch matters more than the box
You will stack and unstack these hundreds of times. The mechanism is the part you interact with, and it is the clearest difference between the two serious systems.
DEWALT's auto-connect side latches clip a box to the one below as you set it down. One hand, no fiddling, no looking. It is the best thing about the ToughSystem design and it is the reason the system is pleasant to live with.
Milwaukee's latches are all-metal and positive, but you operate them. The compensation is that PACKOUT sells every wear part separately — wheels, latches, handle, axle, lid gasket — so a rolling box you can rebuild lasts a decade rather than being thrown away when one plastic part cracks.
The two-system head-to-head in full detail, including the footprint incompatibility, is in PACKOUT versus ToughSystem.
The drawer problem, and who solves it
The real failure of stacking systems is access. A tool in the bottom box of a four-box tower means unstacking three boxes to reach it, which in practice means that tool lives on the bench instead.
Three units here address it, and they publish three different kinds of number:
Klein 54890MB MODbox — three drawers on full-extension ball-bearing slides, one large lower drawer for bulky power tools. Klein publishes no drawer capacity, and the nesting locking bar stores in the base instead of getting lost.
DEWALT ToughSystem 2.0 Three-Drawer — the only unit here that publishes a figure PER DRAWER: 43.5 lb each, across three drawers 65 mm deep internally. Shallow enough that a cordless drill will not fit, which surprises people.
Milwaukee PACKOUT 2-Drawer — 50 lb published total, which is half the plain Large box's 100 lb. Milwaukee states that honestly, and it is the real cost of putting slides inside a box.
The cheap end, honestly
Craftsman VERSASTACK XL and Keter Stack N Roll are both plastic, both have 7 in. wheels, and both cost a fraction of a PACKOUT tower. Neither publishes a capacity for any unit, which is the price of the price.
The VERSASTACK XL is the better of the two: a four-piece tower at 33.9 lb, tested and rated for dust and water resistance, with drop-and-lock stacking and one-touch release. Seven-inch wheels cross a gravel driveway and a curb, which is why cheap small-wheeled towers tip and this one does not.
The Keter is the cheapest way to get 7 in. wheels and a metal telescopic handle at all, and resin will never rust in an unheated garage. The resin latches and hinges are what fail, and they are not serviceable.
#ad · Price as of October 10, 2026 · Affiliate disclosure for the link to ToughSystem 2.0 DS400 Large Tool Box
#1Best for the cheapest sealed big box here
DEWALT ToughSystem 2.0 DS400 Large Tool Box
9.0/10our score, from published specs
The highest published single-box capacity here at 123 lb, IP65 sealed, with auto-connect latches that beat anything Milwaukee does — and usually cheaper than the PACKOUT equivalent.
What the maker publishes
123 lb load capacity — published
IP65 rated for dust and water resistance
21.6 in. W x 14.6 in. D x 16.2 in. H
Patented auto-connect side latches, one-hand operation
Two-piece metal front latches; removable inner tray
Backwards compatible with ToughSystem 1.0
How it scores
Published capacity
9.5
Weather sealing
9.5
Stacking mechanism
9.5
Expandability
8.5
Value
9.0
Where it wins
+123 lb published is the highest single-box capacity on this page, above Milwaukee's 100 lb Large box
+Auto-connect side latches mean a box clips to the one below as you set it down — one hand, no fiddling, and it is the best thing about the whole ToughSystem design
+IP65 sealed, same as Milwaukee's boxes
+Costs appreciably less than Milwaukee's Large Tool Box while publishing a higher number
Where it doesn’t
−Sold in the US largely as the DWST83342-1 international SKU, so the listing you find may be an import with the pricing and support that implies
−Taller and narrower footprint than PACKOUT's, which makes mixing the two systems in one stack a non-starter
−Front latches are plastic-and-metal rather than Milwaukee's all-metal, and they are the part that gets kicked
−Removable tray only; no drawer option within this box
#ad · Price as of October 10, 2026 · Affiliate disclosure for the link to PACKOUT Rolling Tool Box (48-22-8426)
#2Best for the base of a packout stack
Milwaukee PACKOUT Rolling Tool Box (48-22-8426)
8.9/10our score, from published specs
The chassis the rest of a PACKOUT stack sits on: 250 lb published for the whole tower, 9 in. wheels that clear a threshold, and every wear part available separately.
What the maker publishes
250 lb total weight capacity — published
IP65-rated weather seal
9 in. all-terrain wheels and an industrial-grade extension handle
25.6 in. H x 22.1 in. L x 18.9 in. W
Impact-resistant polymer with metal-reinforced corners
How it scores
Published capacity
9.5
Mobility
9.5
Build
9.0
Expandability
9.5
Value
7.0
Where it wins
+250 lb published for the whole loaded stack, which is the figure that actually decides whether a tower of boxes is a good idea
+9 in. wheels are genuinely large — they roll over a garage threshold and a gravel drive rather than stopping dead
+Every service part is sold separately: wheels, latches, handle, axle, lid gasket. A rolling box you can rebuild lasts a decade
+IP65 on the base box as well, so the bottom of the stack is sealed too
Where it doesn’t
−Expensive for a box with no drawers — you are buying the chassis, and the storage is a single cavity with a tray
−25.6 in. tall before you stack anything on it, so a full tower gets awkward to see into
−Rolls on wheels at one end and tips to move, which is fine on a flat slab and tiring on a sloped driveway
#ad · Price as of October 10, 2026 · Affiliate disclosure for the link to Stack N Roll Modular System, 3 Piece
#6Best for light, cheap and rustproof
Keter Stack N Roll Modular System, 3 Piece
7.5/10our score, from published specs
The cheapest way to get 7-inch wheels and a telescopic handle. Resin means no rust and no serviceable latches.
What the maker publishes
3-piece interlocking system: cart, toolbox and organizer
Audible snap latches
Metal telescopic handle with 7 in. wheels and side grips
Resin construction
How it scores
Portability
9.5
Weather resistance
8.5
Capacity
5.5
Spec transparency
4.0
Value
9.5
Where it wins
+7 in. wheels and a metal telescopic handle at the lowest price in this group
+Audible latches tell you the box is actually closed before you tip it
+Resin will not rust in an unheated garage, ever
+Light enough to lift the whole stack into a car
Where it doesn’t
−Resin latches and hinges are the parts that fail, and they are not serviceable
−No published capacity for any of the three units
−An organizer tray plus two boxes is modest storage for the footprint
Where a modular stack lives in the garage
A stack on the floor is a stack you walk around. Both serious systems sell wall-mounting plates, and the pattern that works is a wall rail at chest height with the boxes you use weekly on it, and the rolling base parked underneath carrying the ones you take out.
DEWALT ToughSystem 2.0 publishes the best single-box numbers — 123 lb on the DS400, IP65 sealed, with auto-connect latches that clip a box to the one below as you set it down. Milwaukee PACKOUT has the better chassis, publishing 250 lb for a whole loaded stack on 9 in. wheels with every wear part sold separately. Choose on which capability you need, because the two systems do not interlock.
Do modular tool box systems work together across brands?+
No. PACKOUT, ToughSystem, MODbox, VERSASTACK and Stack N Roll each use their own stacking interface, and footprints differ — PACKOUT is wider and shallower, ToughSystem taller and narrower. Mixing two systems in one stack is not possible, which is why the first box you buy is the real decision.
How much weight can a modular tool box hold?+
The published single-box figures here are 123 lb (DEWALT DS400), 100 lb (Milwaukee PACKOUT Large) and 50 lb (Milwaukee PACKOUT 2-Drawer). Drawer units always publish less than plain boxes because the slides and mechanism take up both space and rating. For a whole stack, the number that matters is the base: the PACKOUT rolling box publishes 250 lb total.
Is a modular system better than a tool chest?+
Only if the tools leave the garage. A modular stack is portability first — sealed boxes, big wheels, a telescopic handle. A rolling tool chest gives you ten drawers, a published per-drawer rating and 200 lb of steel that stays put. If the tools never go anywhere, buy the chest: the best tool chests for a garage covers them.
Which modular system is cheapest to start?+
Keter Stack N Roll, by a wide margin — a three-piece system with 7 in. wheels and a metal telescopic handle for less than one Milwaukee box. The trade is that Keter publishes no capacity for any of the three units and the resin latches are not serviceable.
Sources
DEWALT ToughSystem 2.0 DS400 listing — Published 123 lb load capacity, IP65 rating, patented auto-connect side latches, backwards compatible with ToughSystem 1.0.
