This is a set of four Torx wrenches (T6, T8, T9 & T10 + Makora II Wrench Tool Bit) manufactured by Microtech. These common sized Torx bits will fit many Microtch knives as well as other knives with Torx screws. The bits and handle are all steel. The bits will also fit most any screwdriver with interchangeable heads. The bit heads are held in place with a magnet and the two lose bits fit neatly into the tool’s handle.