3Pcs Motor Axle 3.17mm To 5mm Change Over Shaft Adapter Sleeve For RC Motor | eBay
materials - Motor shaft adapter cannot be removed - Electrical Engineering Stack Exchange
3Pack ShareGoo Metal 3.17mm to 5mm Shaft Adapter Change-Over Motor Axle Sleeve Compatible with Hobbywing HSP 540 550 EZRUN-3656 Motor RC Car Boat Plane