Flexible Coupler (4mm to 6 mm)

From the shop's description

Connect motor shaft to anything else with a set-screw coupler. These couplers are made of machined aluminum and have a spiral cut that makes them slightly flexible so they can be fit to two shafts even if they are not perfectly co-linear and will help reduce bending effects. The way they are cut, create a spring effect in the X Y & Z linear axis but not in the rotational axis. That means that you will not get increased backlash - so they're suitable for precision CNC work. This coupler will connect 4 mm diameter shaft to 6mm diameter shaft . Comes with two sets of double set-screws (two per side) for secure attachment. You'll need a 2mm allen wrench to tighten/loosen the set-screws. 4mm inner diameter / 6mm inner diameter Outer diameter 18mm Height: 25mm