uxcell 3.17mm Airplane Propeller Prop Saver Adapter for Shaft Brushless Motor Product Name : Propsaver;Shaft Hole Dia. : 3.17mm/0.12" Total Size : 10 x 8mm/0.39" x 0.32"(D*T) Color : Silver Tone, Black Weight : 5g Package Content : 1 x Propsaver, 3 x Rubber Adapter Rings