The Irwin Phillips insert screwdriver pozi bits are engineered for use in hand-driving applications or with power tools, designed for use in insert holder with C-clip for retaining ring notch. The bits are compact and versatile with a 1/4 inch hex body and made from high grade S2 steel with a titanium coating.The Irwin IRW10504341 Screwdriver Pozi bits come in a bag of 10 with the following dimensions: PZ1 x 25mm.