It is fully-functionally combination, which including the chain guide, bash guard and chain tensioner.
The top chain guide reduces dropping chain and stables the works, its lifting upper slider's for chain adjustment.
The great strength firm bash guard is able to resist impacting. And the detachable lower roller will act as a chain tensioner.
• Material: Aluminum with CNC Machined
• For 7-12 speed
• Chainring capacity: 28T-36T , ISCG-05 System
• Weight: 118g