Product Description Flat-head screw insert for 1/4" . Technical Information:Blade Material:chrome-silicon-manganese-molybdenum steelSocket Material:CrV steelDrive:1/4"Length:33 mmSizes (FD):FD 4.0 / FD 5.5 / FD 7.0 / FD 8.0 mmManufacturer Numbers:FD 4.0 mm:23737FD 5.5 mm:23739FD 7.0 mm:23741FD 8.0 mm:23742Contents:1 x Manufacturer: PROXXON S.A. Härebierg 6-10 6868 Wecker Luxembourg office@proxxon.com