For the 2018 season, we have revamped our popular X1-B chain guide and made it modular, allowing it to be optimally adjusted to the chainring. The open design allows for installation without the need to remove the crank. The taco can be mounted in two positions to protect either chainrings sized 28-24T or 26-38T. Material: Aluminum 6061-T6 Mounting: ISCG 05 Size: 28-34T or 36-38T Taco: Yes Color: Black/White