There is no need to match the specifications of the electric grinder interface. As long as your electric grinder or electric drill can be clamped to the 3.175mm size, the flexible shaft can be connected. Ergonomic pen design with metal surface allows for easy, comfortable carving, sanding, and polishing, especially during extended use. Installation is convenient and simplejust clamp the connector handle to the electric grinder. The shaft connector must be attached using an electric grinder. (This soft shaft does not include a power tool; tool sold separately.) Compatible with polishing kits, drills, wire brushes, countersinks, flap wheels, mounted points, and grinding wheels. Material: Metal Color: Gold + Silver Package Contents: 1 set x 3.175mm Grinder Flexible Shaft Extension Chuck Only the above package content is included; other items are not. Note: Lighting and display differences may cause slight variations in color. Measurement error allowance is +/- 1-3 cm.