Box One 7sp Rear DerailleurThis top-quality model delivers fast and precise shifting all over the mountain, allowing you to tackle everything the trails have to offer. Its mixed aluminium, carbon fibre and nylon composite construction combines the perfect strength to weight ratio, so you can ride hard through the rock gardens and over tree roots without worry about damage. Additionally, this is a superb replacement for your old or worn-out existing rear mech, which enables you to get back to smooth and crisp shift control.Features: Material: 6061-T6 Aluminum; Carbon fibre/Nylon Composite Hardware: Aluminium/Cr-Mo Alloy Speed: 7 speed Pulleys: Precision sealed bearings Cage Size: Short Cage Maximum Cog: 24T Technologies: Adjustable tri-pack limited slip clutch, pivot tech Weight: 279gTechnologies: Adjustable Tri-Pack Limited Slip Clutch: The Adjustable Tri-Pack limited slip clutch is an innovative chain damper that vastly reduces derailleur cage bounce and chain slap. The system also maintains tension for better chain wrap. At its core is a clutch pack, that is capable of providing a large amount of force in a small package. Clutch force can be adjusted to give the user the ability to tune their setup to the desired balance of shifter feel and chain retention. This version is also serviceable. Durable 3D Forged Linkages: Impact resistance is greatly improved by way of forging — a key manufacturing process that strengthens critical components. Tested at the premier freeride event of the season — Red Bull Rampage — this new construction has proven itself capable of performing at the highest level. Pivot-Tech: Impact resistant, spring-loaded cable stay keeps cable, housing & you out of harms way.Buy Box Components from Chain Reaction Cycles, the Worlds Largest Online Bike Store.