The Burgtec Thick Thin Chainring is designed and manufactured in the United Kingdom, and has been tried and tested in the Peak District. This chainring is the perfect upgrade for your 104mm PCD compatible drivetrain. You won't need a chain device with the Thick Thin as your chain will be held perfectly in place, no matter how rough the trails get. The Thick Thin is a perfect low-cost upgrade, offering exceptional durability and performance. It is made from lightweight and durable 7075 T6 aluminum to ensure maximum endurance, keeping your chain on. It is compatible with any crank that uses a 104mm PCD chainring pattern and is designed to work with clutch derailleurs to keep your chain from dropping off even on the roughest of trails. This chainring is the perfect partner for Shimano cranks.