This extended length plastic mount allows you to take full advantage of all the data that your Edge provides The Edge is out in front of you for easier, heads up positioning and increased safety Fits 31.8 mm bars Compatible most imprtantly with Edge 1000 but also with Edge 810, 800, 510, 500, 200, plus Forerunner 310XT, 910XT with the quick release kit Weighs just 30 g Made from impact resistant plastic Please note for the mount to work with the Forerunner 910XT or 310XT you must remove the screws from the bottom, rotate the inner-mount and reinsert the screws, and your watch will mount in the proper orientation on the handlebar