The 21 can capacity leaves ample space for ice or cold packs: the manufacturer has left one third of the total volume for this use in the 21 can estimate. If using together with separately available padlocks, the Tundra is IGBC approved as a bearproof container. The manufacturer doesn't skimp on materials, quality, or cool (pun intended) names of different parts of their products with registered trademarks: - *Doublehaul* carrying handles - *Lipgrip* side handles - *T-Rex* buckles - *Fatwall* structure with more than 3" of insulaion - *Permafrost* insulation - *Interlock Lid* - *Coldlock Gasket* - the same sort of a gasket you'd see in freezers - *Neverfail* hinges are made to last - *Bearfoot* material on the bottom prevents the cooler from sliding around - *Anchorpoint* system for strapping the cooler down - *Vortex* draining hole means you don't have to tilt the cooler for draining