CHAIN CHECKER: This precision laser-cut chain checker is designed to accurately measure when the chain reaches a .75% or 1.0% stretch and decide the necessity of chain replacement. Place the checkers onto a segment of the chain then see whether the chain checker lies completely flat on the chain. If so, replace the chain. Compatible with 7 to 12 Speed Chains including Shimano Sram Campagnolo KMC and other brands. CHAIN RIVET TOOL: A professional tool that can effortlessly install and remove the chain rivet without damaging the chain, features a spare driving pin. The precision-designed pin screws into the chain, with an adjustable clamp that suits chains of various widths, and a steel-constructed body with a contoured cushioned handle. Compatible with any bicycle chain, from a single speed up to 12 Speed and half-link single-speed chains. MASTER LINK PLIERS: This tool is made to easily remove and assemble the master link by inserting it into the master link and then squeezing it with the handle to close(dissemble) or open (tighten)the link. There will be no difficulty for stiff, corroded, or tough links when used. Compatible with 5 to 12 Speed chains that use a master link, including brands such as SRAM, AXS, and Shimano.