DURABLE MATERIAL: Made of durable 50# steel for long-term use. EASY TO USE: No tools required to remove the cleaning chain, suitable for mountain biking and racing. Reuse: The magic buckle can be reused up to five times; easy to disassemble and maintain. Assembly Instructions: 1. Install the chain correctly, clean and lubricate the bearings. 2. Don't forget to oil the pen. 3. Insert the two halves of the clasp into the end of the chain. 4. Press down on the two halves of the cufflink connector. 5. Open the chain to lock it. 6. Turn on: Push the two boards together at the same time, and push the chain ends together. Quantity: (4 Pair Pack) Bicycle 10 Speed Chain Linker, other products not included Color: Gold Note, because there may be color and size difference between the light effect photo and the actual product, please allow 1-2 cm error