The hose barb union is used for connecting two hose of same size, they has barbed ends to create a tight seal on a hose when used with a hose clamp ( included). The union is made of stainless steel 304 for greater strength.They are used in patio, lawn garden hose connect, Irrigation, lawns, air compressors, automatic manufacturing operations, aircraft controls, and tire installation in industries including agriculture, mining, road construction, firefighting, and aviation