Ultimate Arms Gear Meprolight S&W M&P FULL SIZE/COMPACT/SUB-COMP FRONT TD 3/32 Pin Punch Armorers Tool Package Includes: Meprolight ML11766F.S + Ultimate Arms Gear Pro Disassembly 3/32 Pin Punch Armorers Gunsmith Tool Ultimate Arms Gear Tool Diameter is 3/32 of an inch or 2.5mm. Small and compact with enough size and strength to do all that is needed in taking apart pins and putting it together.