Note: The color of the item may vary slightly due to photography and your own computer Specifications: Connected to the motor shaft length = 22mm inside diameter = 3.18mm access shaft = 4mm 3.18 x 4mm lock, commonly used in the brushless electric boat motor shaft is 3.175mm, 4mm shaft then used mainly to connect the motor and the shaft as a whole, the motor drive shaft above the propeller to achieve thrust, CNC aluminum alloy Weight:10g Size:0.87x0.39 Color:Silver Package Included: 1 x Brushless Electric Boat Cable Head