This product includes :hex-2PCSstainless steel screw shaft M4*2.5*11.8-2PCS5mm hole spring steel round head washers-2PCS5mm hole steel ring with open end-2PCS11mm hex screw-2PCSManual number: 8269+8270+8271Product major function & usage:
wider hex to achieve wider wheelbase onroad tires for better driving experience easy to assemble, high quality durable tires with aluminum 6061T6 hard anodized wheels for onroad setting