Monitor your performance as you ride with this easy to install wireless speed sensor the speed sensor attaches to the hub of either wheel and self calibrates with your garmin edge to give you accurate speed and distance at all times even when indoors on the turbo trainer or in areas where gps signal is interupted compatible with the edge 1000 810 800 510 500 910 xt 310 xt as well fr610 and fr70 series watch units pack includes speed sensor speed sensor sleeve manual