Texas Pneumatic Tools Chicago style, universal hose couplings or crowfoot fittings connect hoses & air tools to compressed air systems in air and water applications. They are sealed by pressing & twisting together with hose barbs and include rubber washers to prevent leaks & dampen vibrations. These jackhammer couplings have lug design (selected models) to create secure leak-free connections & are available in MPT (male pipe thread) & FPT (female pipe thread) fittings.