FIFTY-FIFTY 1X DH LITE Series ISCG05 Chain Guide 32-38T Alloy Aluminum(Black/White) The high molecular nylon parts increase shock absorb, wear life, and reduce friction and noise. Super light 4mm full machined 6061 T6 aluminum backplate. Full machined alloy hardware(upper cage/bashguard fixing bolts). Adjustable upper cage and roller with chainring range indicator. Ultimate silent polyurethane roller with awesome mud shedding performance and extended life.