GSR General Service Respirator gas mask pouch CBRN NBC filters Sz4 Small. The item “GSR General Service Respirator gas mask pouch CBRN NBC filters Sz4 Small” is in sale since Thursday, March 26, 2020. This item is in the category “Collectibles\Militaria\Current Militaria (2001-Now)\Original Items\Personal, Field Gear\Gas Masks”. The seller is “perfettoperformance2010″ and is located in Glenview, Illinois. This item can be shipped to United States.