C.K T4690M 23 Hex head Bits 23 mm 1/2 (12.5 mm)

5) Forged Chrome Vanadium steel for superior strength & durability6) Non slip, satin chrome plated for resistance to rust & peeling7) C.K 'Sure-drive' system applies torque to the flat of the nut rather than the corners to avoid rounding off

Price: 7.49 from Conrad Electronic