Features1Applicable Model: The chain tensioner is for Brompton Pline Tline, for Cline after modification. Please confirm whether it is consistent with the product you want before buying to avoid unnecessary return. 2Sturdy and Reliable: The rear derailleur chain tensioner provides strong fixation for reliable durability, extending the lifespan of your chain. It also can be a great addition to enhance stability and performance. 3Simple Adjustment: The chain stabilizer is suitable for 5 6 7 speed rear derailleurs, allowing for easy chain tension adjustments that provide smoother rides. 4Enhanced Safety: The chain guide adjuster features a unique tension arm design that effectively stabilizes the chain and minimizes chain skipping, enhancing overall safety on the road. 5Easy to Install: The chain converter is easy to install without the need for professional tools, giving the user the convenience of making adjustments on their own.SpecificationItem Type: Rear Derailleur Chain Tensioner Material: Aluminum AlloyGuide Wheel: 8TFitment: Fit for Brompton Pline Tline, also for Cline after modificationPackage List1 xRearDerailleurChainTensioner