This is a genuine part which is supplied directly by the original equipment manufacturer and is used with Waring spice grinders. The coupling spins on the motor shaft to rotate the blades that grind the contents of the unit. This part is made of plastic and is sold individually. To remove an old coupler, just place a flat head screwdriver...Read more underneath the coupler and gently push up while rotating it. Then simply screw on the new coupler afterword.