E thirteen trs dmb dual ring chain guide you dont have to run a single ring anymore the trs dual guide will keep your 2x system silently in place on the most demanding rides the trs trail security dual guide is designed to fill the expanding enduro and all mountain categories engineered to take extreme punishment dealt by riders on enduro bikes features designed to work perfectly with your 2x10 or 2x9 speed set up and in conjunction with your front derailleurhigh tensile crmo steel backp