Octura Flex Hex Coupler 3/16"(.187, 4.75mm) to .150 (3.81mm) Cable Fits some of the Astroflight Motors. Specs: Motor size 3/16" (.187", 4.75mm) Flex Cable size .150" (3.81mm) Length 1.00" (25mm) long Diameter .50" (13mm) at widest point