1. With the flexible hose, you can work in tight spaces. Thick hoses and extended fixing rings make the flexible shafts more robust and durable. 2. There is no specification for the corresponding interface of the electric grinder, as long as the electric grinder or drill can be interposed. A size of 6.5 mm, easy to install, just attach the power connector handle to the grinder. 3. Installation is convenient and simple, just attach the connector handle to the electric grinder. The shaft connector needs to be connected using an electric grinder. 4. Use to extend power tools for grinding small workpiece in a specified area. Specification: Material: Metal. Arbor Installation as attached picture: 1) Remove the rotating collet nut and top cap from the rotary tool. 2) Slide the collet nut onto the arbor core. 3) Insert the arbor core into the collar. 4) Tighten the collet nut. Make sure the arbor core is securely held in the instrument. 5) Screw arbor connector onto the rotary tool. This will ensure the shaft core is pushed into the shaft. Bit Installation Instructions: 1) Insert the included L-bar into the hole on the side of the shaft clamp. 2) Unscrew the shaft clamp nut. 3) Insert the bit, not included, into the shaft clamp. 4) Tighten the shaft clamp nut. 5) Remove the L-bar. Package Contents: 1 x Flexible Shaft. 1 x Handle. 1 x Wrench.