Mrp mini g4 chain guide alloythe g4 is a direct upgrade over the infamous g3 guide the new full size upper guide with tpu material on the interior walls silences chain contact the integrated skid plate protects the chainrings on your crankset and also glides over rocks and obstacles featuressuited to downhill gravity and enduro ridingfor use with mini chainring sizes 32 36tsingle ring 1x 78910 and 11 speed drivetrains full size nylon upper guide with co moulded tpu material silences