isoar mtb mountain bike crank gxp to bcd 104mm spider adapter for sram gxp xx1 x0 x9 crank offset 6mm isoar <p> support crank: sram x9/xo/x1/x01/xx1,only for signle speed<br /> material:7075 aluminium alloy<br /> easy to install, durable<br /> light weight, 40g<br /> anodizing<br /> <br /> packing: one adapter + 4 chainring screws </p>