Yeti Tundra 45L Cool BoxYeti Tundra 45L Cooler Rotomolded construction, For virtually indestructible protection T Rex lid latches which are heavy duty, patented, and made to never bust Never fail hinge system, interlocking two pin design that prevents breaking Fatwall design holds up to three inches of insulation Permafrost insulation Pressure injected polyurethane locks in that just packed temp Interlock lid system that creates a form fitting barrier against extreme temps