Description 1/2 Inch Aluminum Key Hub 18083 Designed to connect a motor and a wheel Material: Aluminum-alloy Inside diameter: 1/2 inch Outside diameter: 56.8 mm Bore Length: 26.4 mm The 1/2 Inch Aluminum Key Hub 18083 is designed to connect a motor and a wheel. There is a groove of key locked for securing a motor to the hub. View more What's Included 1x 1/2 Inch Aluminum Key Hub 18083 Dimensions Size Inside diameter: 1/2 inch Outside diameter: 56.8 mm Bore Length: 26.4 mm Specifications Material: Aluminum-alloy Weight: 67.9 g