Chain Guide Mountain Bike, CYSKY MTB Chain Guide Direct Mount Chainring Guard Perfect for Most Bicycle Road Bike Mountain Bike BMX Fixie (Alloy Aluminum, Black)

About this item Seat tube clamp chain guide, prevents the chain from dropping off the upper side. Seatpost diameter 35mm (With ø31.8mm to ø35mm shim) Compatible: fit bike with 1x drivetrain systems Material: Alloy 6061-T6,Plastic top guides. Extremely easy to install and adjust using a single 4mm Hex tool, without removing your cranks.