button style and colour may vary but most are the black ones seen in the photos

These are general issue through the RAF so it's quite a common site around air bases given the usual British weather

outdoor adventurers

all of which can be buttoned shut

Czechoslovak Army M10 Gas Mask & Bag Kit - #2 Helmet button style and colour mayAt a glance Unissued Deadstock Water Resistant Vinyl Carry Bag Includes; 1 Mask, 2 Spare Lenses, 2 Filters, Instructions, 2 Cap Filters Heavy Duty Rubber Material Adjustable Shoulder Strap Grey Mask Solid Olive Drab Bag Colour Bag measures Measures approx. L 7. 5" x W 4. 5" x H 11. 5" Vintage Militaria Issued around 1988 Used in both Czechoslovakia, East Germany, Slovakia & Czechia Genuine Czechoslovak People's Army Surplus Grades Grade 1 Good