This is an adapter for attaching a Cateye cycle computer to a Garmin mount. It was included in a set of parts I purchased used, but I don't own a Cateye cycle computer, so I'm selling it. I've confirmed that it fits a Garmin mount without issue, but I haven't been able to test it with a Cateye cycle computer. It's likely unused. Discounts are available for bulk purchases. Thank you for your consideration. Cateye Garmin Cycle computer Mount Rec-Mount