Chrome vanadium, drop forged, impact, contents: 1 pc 3/8 dr. Universal joint, 2 pcs reducers: 3/8(f) to 1/4(m) and 1/2(f) to 3/8(m), 2 pcs adapters: 1/4(f) to 3/8(m) and 3/8(f) to 1/2(m), weight: 0.35 Lbs.