E Thirteen Direct Mount M Boost GuideringThis superb model ensures superior chain retention and is optimised for boost spacing. Its tooth profiles and chamfers deliver much better chain retention than standard chainrings thanks to their long-wearing shape and finish. Furthermore, it will stay secure even after months of use, so you can enjoy endless hours of smooth and efficient gearing.Features: Material: EXA+ Aluminium Mount: Direct Mount Thickness: 5mm Compatibility: TRS, TRS+, TRSR Suitable For: 8, 9, 10, 11 speed BOOST version Weight: 82g (32T version)Buy E Thirteen Components from Chain Reaction Cycles, the World's Largest Online Bike Store.