Material: Forged from carbon steel for hardness and toughness. Blackened phosphate treatment body for rust-proofing and wear-resistant. New Version now including some multitool Functions Easy to Use: When the Chain Wear Checker indicates at 0.75 (75%) wear, it is time to replace the worn chain. Essential Tool: The Bike Chain Checker is an essential tool for any cycling enthusiast or mountain biker. Bike Chains wear after intensive use. A worn chain can wear down bike sprockets. Avoid expensive repairs by simply checking your chain regularly with this simple but important tool. Compatibility: The Chain Wear Indicator can be used with all bike chains for any bike type: City Bike / E-Bike / Mountain Bike MTB / Race Bike / Folding Bike. Product provided by MMOBIEL - We always try our best to exceed your expectations at every turn. Join the ever growing list of satisfied customers and discover the difference with MMOBIEL.