TL-CN42 Chain Wear Indicator

You've been saying you last replaced your chain a few months ago for more than a few months now, and if pressed, you'd have to admit you don't actually know how old it is anymore. Rather than waiting until you're 30 miles into a Saturday 60-miler and your chain falls off mid-shift, you could invest in Shimano's TL-CN42 Chain Wear Indicator to keep an eye on how much life your chain has left in it when you can still do something about it. Made with durable heat-treated stainless steel, the Chain Wear Indicator uses a three-pin structure to measure the give in your chain, and takes just a few seconds out of your pre-ride ritual to check.