3x4mm Rigid Brass Short Coupler
This fancy coupler is designed to be assembled onto any threaded 3mm diameter shaft and 4mm rod or screw. Commonly used for coupling threaded axles to shafts to transfer the rotational movement. This unit comes with two M4 hex grub screws and an M4 Philips screw for fastening onto the rods and motor shaft.
Price is each.