5mm to .187" reverse threaded style stainless steel coupler. Used on reversed cable systems such as the Zonda. Specs: Measures: 35mm(1.38") long x 11.8mm (.46") diameter. Motor shaft: 5mm motor shaft Flex cable: 4.75 (.187") flex Cable M4 grub screw Requires:2mm hex driverNOTE: USE only with reverse rotation cables.