Sockets forged from chrome molybdenum steel, hardened, tempered and chemically blacked for corrosion protection. Hole for accessory spring loaded ball. Packed in plastic storage case.|9 x 3/8" sockets: 8, 9, 10, 11, 12, 14, 15, 16, 17mm10 x 1/2" sockets: 13, 15, 17, 18, 19, 21, 22, 25, 27, 30mm10 x 1/2" deep sockets: 13, 15, 17, 18, 19, 21, 22, 24, 27, 30mm1 x 1/2" (F) x 3/8" (M) adaptor1 x 3/8" extension bar: 75mm1 x 1/2" extension bar: 75mm|Safety Note: ONLY impact sockets and accessories can be used with air or electric powered wrenches. NEVER use silver chrome vanadium steel sockets which can shatter and cause personal injury.