Bontrager's Handlebar Bottle Cage Clamp lets you easily attach a water bottle cage to your handlebars so your hydration is always within reach. All hardware is included and it mounts to road, mountain, and city bike handlebars with a 31.8mm diameter. - Alternative water bottle placement solution for bikes without mounts on the frame - Clamp only (cage sold separately), fits 31.8mm bars - Includes mounting hardware to affix clamp to bar