These are the toughest storage systems on the market! I was actually surprised to feel something so sturdy from dewalt so I had to check to see where it was made, --Israel of all places! System works great clicking together, strong enough to stand on, drop, have things fall on it etc, and water tight! I have festool systainers so this is really saying something for dewalt, well done! My systainers still get used for shop work but for site work these are the go to.
edit, 3 years on: I ran over one with my f-350 and the only damage was a crack. They are amazing. They are better made than bosch, festool (tanos), makita, put together. They are for jobsite construction, not woodshops. Absolute Tanks.
If you're only interested in this product being waterproof, and/or air tight.... they fail, miserably. I have two of them....different sizes, and they both suffer the same flaw, created during the molding process. In short, the bottom ridge does NOT come in contact with the upper yellow flex seal, and therefore.....allows air, and moisture to enter. It is possible to correct this issue, by simply temporarily removing the yellow seal at the Left & Right side handle locations [the offending area that is not flat, on the bottom portion of the box] on the top lid assembly....adding some silicone sealant in the trough, and than.....carefully pushing the yellow seal back into it's slot, but not "too far"...so that it will now come in contact with the lower half of the box where the contacting ridge is located.