Multipurpose hose fittings and couplings are parts that connect multipurpose hoses together in a pipe system. They are often used to link hoses that have different thread types or sizes. Multipurpose barbed hose fittings have raised ridges that grip the insides of hoses to hold them firmly in place. Multipurpose quick-connect air couplings are used in industrial pneumatic applications to connect air tools and hoses to compressed air supplies. Multipurpose reusable hose fittings screw onto hoses and can be unscrewed and used again. Multipurpose threaded swivel air line fittings help control air hose lines to prevent twisting and kinking.