Why purchase a digital chain checker that is pretty pricey versus a simple go - no go model? For starters, your chain is generally the least expensive regularly replaced component of the drivetrain. Second, it wears with every use and conditions as well as riding style and weather can all impact wear. Third, if you change your chain regularly as the wear indicates as well as use proper lubricant, you can preserve the rest of the drivetrain- all of which is more expensive. Chainrings, cassette cogs, and pulley wheels The result? Your shifting will be more precise, and in an absolute worst-case scenario it won't break under load due to excessive wear. The KMC Digital Chain Checker has a patented design, is extremely accurate and will encourage you check your chain wear more frequently. All the options and information you need are listed on the checker, and a simple emoji-based quick reference guide on the tool make it easy to identify wear ranges for both standard rear derailleur and internal hub drivetrain systems.