Draper Cross Slot Impact Screwdriver Bit, No.3. This is an 8mm hexagon shank bit suitable for use with Stock Nos. 22322 and 81519 Impact Screwdriver Sets. Sold loose. Specifications: Type: Impact Driver Bit, Drive Type: 1/4" Hex, Head Size: PH3, Head Type: Phillips, Number of Pieces: 1, Overall Length: 25mm.