Note: 1. If the surface of the break screw is smooth, you need to drill a hole first. Otherwise, the drill bit will slide off. 2. When drilling must be vertical, low speed. Use this drill bit in reverse direction. Makes it easier to remove the first hole more deeper. 3. We recommend using an electric hand drill instead of the hammer drill mode. Slow speed while in use. Specifications: Material: High Speed Steel 4241 Size: Adapter: 1.0 x 0.2 inches (26 x 4 mm); Extension Bit Holder: 2.4 x 2.5 inches (60 x 6.35 mm); Quick Release Extension Bit Holder: 2.0 x 2.5 inches (51.2 x 6.35 mm); Features: 1. High Speed Steel 424241, high hardness, durable, easy to remove damaged screws. 2. Suitable for general size and various broken bits. 3.Surface is anti-rust and anti-corrosion, improve working efficiency. 4. Universal chuck suitable for most electric hand drills 5. Suitable for allen bolts, lag bolts, hex bolts, machine screws, wood screws, sheet metal screws and other screws. Package Includes: 10 x Drill 10 x Extractors 10 x Driver Bits 1 x Socket Adapter 1 x Extension Bit Holder 1 x Quick Release Expansion Bit Holder [How to Use] Step 1: Size #1-#5: The drill is installed directly into the extension bit holder Size #6-#10: First install the drill into the socket adapter and then install it to the extension bit holder Step 2: Using the drill (Dr) bit holder. counterclockwise. open. Requires vertical and slow speed (RPM≤200) Step 3: Change to use the same size of extraction (Ex) bit Step 4: Use reverse drill to remove broken bits