Made of high quality metal The spline fits with the splined wheels for 17mm. Perfect style and exquisite workmanship. With screws, easy to install and for long time use. Color: Black Material: Aluminum alloy Package Contents: 8 x Combiner 2 x Screwdriver Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in a little different from the real thing. The measurement allowed error is +/- 1-3 cm.