Bicycle Chain Adjuster Aluminum Alloy CNC Bicycle Chain Fastener DIY Modification Feature: 1. Lightweight: The bicycle chain tightener is made of high-strength aluminum alloy with lightweight design, wear-resistant and anti-corrosion. 2. Bright Color: Not easy to fade, more beautiful. Effectively prevent the chain from falling off the frame and damaging the frame surface. 3. Applicable To: The split zipper adopts CNC technology, which is mainly used to adjust the chain tightness for folding bicycles. 4. Easy to Install: Easy to install without complicated tools. Suitable for road bicycles. Specification: Main material: Aluminum alloy Product color: Black, Red, Gold, Silver (optional) Product size: About 36x20x12mm/1.41x0.78x0.47inch Net weight of product: About 10.3g Package includes: 1 x Bicycle Chain Adjuster or 2 x Bicycle Chain Adjuster Note: Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! Please allow 1-2cm measuring deviation due to manual measurement.