MRP AMg SLR Chainguide - 32-36t ISCG-05 Carbon Backplate. The MRP AMg SLR chainguide eliminates dropped chains and bent chainrings. It combines a lightweight upper guide and a durable bashguard mated to a carbon fiber backplate. Unlike the cheap flexy and rattle-prone upper guides found on other products the AMg features a premium stiff silent upper guide and a tough fiber-infused bashguard.