Amazon.com: DNA High Performance Air Filter for Suzuki GSR 600 (06-11) PN:P-S6S06-01 : Automotive
MKIV GSR with Type E MkV. The date of the filter, September 1939, is interesting as I didn't think they were making MkV filters this early. Some info in comments. : r/gasmasks
GSR air filter guard - water and dust shield
GSR Pumps and Filters | Mbombela
Scott GSR Gas Mask Filter Set
GSR | Gas Mask and Respirator Wiki | Fandom
Used Filter for GSR Gas Mask by British Army
GSR (general service respirator) spare canister filter British Army - Walk This Way