Andoer Bike Mount Holder Handle Bar Computer Mount 25.4mm / 31.8mm for GARMIN Edge 200 / 500 / 510 / 800 / 810 GPS Rock solid, stiff & secure grip. Easy to fit - no need to remove tape/grips/levers etc., simply opens up and you bolt on with a hexagon wrench. This is not the inferior cheaper style that snaps when you do this, or in cold weather! Sits in front of your stem/bar so you can look at your Garmin easily, keeping your eyes on the road/trail as well. Compatible with computers with 1/4" turn twist lock interface. Basically it's used for Garmin with 1/4" turn twist lock surface. The clamp size of this GPS mount is 31.8mm for handlebar. What's more, the inserted spacer to make it also fit 25.4mm diameter handlebar.