Chains are the lifeblood of your drivetrain. Without one, you have nothing more than a glorified hobby horse. And when they break, it's typically due to sloppy installation. When a professional mechanic installs a chain, it's with a precision unit like this Park Tool CT 4. 3 Master Chain Tool for a reason. Field service and home mechanic tools work great in a pinch, but if you want to avoid the pinch altogether, the only way to go is professional grade. Aside from the obviously ergonomic handle, the CT 4. 3 works with the tight tolerances of modern, narrow chains due to its investment cast, precisely machined body. This ensures that the tool's pin is guided straight, and that it doesn't wander while installing the chain pin. Otherwise, wallowing of the bore, binding inside, or bending of the plates will happen. Additionally, the pin is easily replaced if it happens to bend. Another defining feature of the Master Chain Tool is an integrated link pocket for precise alignment during use. The Park Tool Master CT 4. 3 Chain Tool is compatible with Campagnolo chains, and includes an anvil to peen their 11 speed chains. It will work with all 5 through 11 speed chains from Shimano and SRAM, as well. Please note that the only chain that it's not compatible with is Wipperman.