Meprolight The Mako Group ML10990 Ruger P89 Tru-Dot&reg; Night Sight Set + Ultimate Arms Gear Pro Disassembly 3/32 Pin Punch Armorers Gunsmith Tool Package Includes: Meprolight ML10990 + 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.