Equipment made for a S.T.A.L.K.E.R.: Shadow of Chernobyl / Clear Sky - inspired costume.
I made this in October 2007, and wore it on Halloween that year, and then, in modified form, to Anime LA '08.
Simple, quick build:
The tanks are cheap fire extinguisher bodies, mounted to an old camping backpack frame. Piping is just generic home depot stuff. The radio is an obsolete, semi-broken police scanner. The gauge is from an air compressor regulator, and I modified it to include an LED so that the face lights up at night. The hose is actually intended for a sump pump or a vacuum cleaner, and the mask is a modified painter's mask, which attached to a ski mask with velcro. Goggles are really intended for welding, and the helmet is a plastic replica.
Most of the work is in painting and weathering. I banged everything up a bit, and then sprayed several coats of olive drab, with random bits of sand between them to make everything look "gritty", followed by a generous amount of silver drybrushing to simulate paint scrapes. The effect was quite convincing, people were shocked that the whole thing wasn't made of steel!
The guns are just cheap airsoft, all I did was a bit of weathering, and I sprayed the AK-47's furniture green to replicate the AK-74 in the game. (there wasn't a cheap enough AK-74 on the market at the time to ruin for cosplay.