The Irwin TORX insert screwdriver bits are engineered for use in hand-driving applications or with power tools. They are designed for use in an insert holder with C-clip for retaining ring notch. They are compact and versatile with a 1/4 inch hex body and made from high grade S2 steel.The Irwin Screwdriver TORX bits come in a pack of 2 with the following dimensions: T20 x 25mm.