Includes 16 pieces SAE hex bit sockets Our socket can be locked securely on to your ratchet handle and turns even the toughest fasteners. 1/4″ Drive: 2mm, 2.5mm, 3mm, 4mm, 5mm, 5.5mm, 6mm. 3/8″ Drive: 7mm, 8mm, 9mm, 10mm, 11mm, 12mm.