Wheeler Professional Gunsmithing Add-On Screwdriver (21-Piece), Black Great addition to the 72 or 89 piece Wheeler Gunsmithing Screwdriver Sets Hex bits: 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 7mm, and 8mm Torx bit: T6, T7, T8, T9, T10, T15, T20, T27, T30 Comes with plastic storage tray and hollow ground flat bits made of durable S2 tool steel 1/2" x 1/4" socket driver