Available in 2 Spindle Interface Mode:Diamond Interface and Square Interface. Hole spacing length:170mm; total length:210mm Color: black Material: Aluminum alloy package include: 1 x bike Crank Arm Note 1: Please check the interface of your right crank arm is square or diamond. Keep both left and right arms have the same hole; Some GYM bikes may not be available, please confirm the length and connection port; Note 2: If you have replaced the crank once, then you need to replace the bottom bracket when you update the crank again, because the life of the general bottom bracket is only 2 times. Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.