Description: Stainless Steel Flex Collet Coupler 3.17mm Motor Shaft And 4mm Cable For RC Boat   Specifications: Compatibility: 4mm shaft and 3.17mm motor shaft Material: Stainless steel Length: 31mm Inner Diameter (connect motor shaft): 3.17mm Inner Diameter (connect flex shaft): 4mm   Features: This stainless steel flex coulper \/ collet with one grub screw fits for 5mm motor shaft and 4.76mm (3\/16!#!amp!*!quot;) flex cable for rc boat. It's for round end cable.   Package Included: 1PC x Flex collet coupler   More Details: