Nickel chrome plated for corrosion protection. Maxi Drive ring ends for increased grip & reduced fastener damage. Forged from chrome vanadium steel to ISO 3318 & DIN 3113 for proven performance. Re-usable plastic rack for easy storage. 13 piece set comprising: 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm & 20mm.