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 with metal surface makes easy, comfortable carving, sanding and polishing, especially for a long time use. The installation is convenient and simple, only need the connector handle be clamped to the electric grinder. The shaft connector needs to be connect by electric grinder.(This soft shaft does not have a machine, another machine). It can used with polishing kits, drill bits, wire brushes, countersinks, flap wheels, mounted and grinding wheels. Material:Metal colour:Gold + silver Package Contents: 1 set * 3.175mm Grinder Flexible Shaft Extension Chuck Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.