Expert Quality, chrome vanadium steel hardened, tempered and chrome plated. Each component has been tested to 10,000V for safe 1000V AC or 1500V DC live working. Packed in tough plastic storage case. Contents: 20 x Fully insulated sockets: 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 27, 29, 30, 32mm, 1 x Fully insulated reversible ratchet with quick release button, 1 x Fully insulated extension bars: 75, 125, 250mm. Manufactured to DIN Standard and individually certified to EN 60900