Compatible with the Essential8 only 2mm hex,#2 is an optional bit and can be chosen to replace 2mm,2.5mm Hex The #2 Philips head bit fits common screw sizes, tip measurement of 3.5 mm. Corrosion resistant stainless steel Black PVD coating on the 4mm, 6mm Hex, T25 bits Adapter bits feature Neodymium magnets