Stone Glacier | Grumman Down VestUltralight, ultra packable down insulation worn over base and mid layers and underneath a shell while hunting in cool to cold conditions to keep the core warm without infringing upper body mobility. Weighing less than the four Pop Tarts you ate for breakfast, the Grumman Vest shares the same big tech specs as the Grumman Jacketnow in a smaller package. Inside, find 850+ fill treated goose down. Outside, find a 15 denier Pertex Quantum shell. Use it as