Our 4PC Replacement Bits include ECX #1 and ECX #2, Phillips and in Slotted, Phillips and 3/16in Slotted, and Square and #1 Square. The driver bit set is compatible with the MILWAUKEE multi-functional screwdrivers and offers you the most common bit sizes. These bits are double-sided for compact convenience with engraved markings for quick identification. This 4-piece bit set has a limited lifetime warranty.