Model RC Boat Complete Coupling to join a MFA Torpedo 800 & 850 Motor to a 4mm M4 Threaded Propeller Shaft. This includes: 1 x 1/4th coupling with grub screw for the MFA Torpedo 800 & 850 sized motor 1 x Universal joint (joins the 2 brass couplings) 1 x 4mm threaded coupling for the M4-4mm threaded propeller shaft The coupling tightens to the motor using the grub screw and screws onto the shaft using the thread. (Please note: Motor shown in image not included and is for display purpose only, to show suited motor)