ProTool 3/8" Drive X 15mm Deep-Well Socket - Steel - Accepts Bolts Up To 1-3/4" 3/8 inch drive, 15mm - Deep-well version will accept bolts up to 1-3/4" length Drop forged from extremely strong chrome-vanadium steel alloy for superior longevity & durability Chromium added to the alloy helps increase resistance to abrasions, oxidation & corrosion - Cleans easily Ridged edge helps increase grip while turning socket with oily hands 6-point deep-well design increases socket grip on nuts & bolts - reducing likelihood of stripping