Army Small Box Respirator Gas Mask & Filter – With Instructions – Complete Set. Army Small Box Respirator gas mask set – complete with mask, hose, green filter canister, and instruction booklet. One eye piece is cracked as seen in picture but structurally intact, also the black interior lining is flaking so be aware of that. The mask’s structure has been squished but isn’t in danger of falling apart. Original WWI gas mask with head straps. Flexible cloth-covered breathing hose. Original green-painted filter canister. Original instruction booklet: “This Envelope Contains Instructions, Record Card, Tape for Repairs”.