Park Tool CC-4 Chain Wear Checker Look And when you start to

And when you start to sweat as you climb or prepare to drop in on a descent

secure fit

Whether you're braving wet weather or muddy trails

Removable bombshell ear pads for form-fitting comfort

calf-hugging fit

Park Tool CC-4 Chain Wear Checker Look And when you start toA worn bicycle chain causes poor shifting performance and can actually wear out drivetrain components, causing more expensive problems. The Park Tool CC 4 Chain Checker is a drop in style gauge that measures bicycle chain wear. The laser cut CC 4 accurately measures a long section of chain and strategically comes in contact with the chain in three places, quickly and easily taking the guesswork out of determining when chain replacement is necessary.