US Marine Corps Tan FROG Waffle Grid Thermal Bottoms f-1b varies by contract• Function: External

varies by contract• Function: External side pouch for modular assault pack storage and load carrying systems

Large transport stuff sack with a drawstring closure

Issued to Marines as a cold weather mid layer for use in both garrison and deployment

Army personnel as the outer shell of the Modular Sleep System during the UCP uniform era

US Marine Corps Tan FROG Waffle Grid Thermal Bottoms f-1b varies by contract• Function: ExternalThe US Marine Corps tan FROG waffle grid thermal bottoms are flame resistant base layer trousers designed to provide insulation and moisture management in cold weather environments. Their waffle grid construction helps retain warmth while maintaining breathability during field operations. Color: Tan Material: Flame resistant synthetic fabric Function: Thermal insulation and moisture management for cold weather operations Issued to U. S. Marine Corps