Sorel - Caribou Inboot (Off White) - Men's: Pioneered by Sorel in 1993 after extensive field testing. ThermoPlus InnerBoots provide superb warmth, moisture transfer, comfort, and durability. Advanced four-layer construction wicks perspiration from the foot, maximizes thermal insulation, and uses Radiantex(R) foil to reflect body heat back to the foot for a warm, dry foot climate.