The CTP-4K includes four replacement chain tool pins and one 5/32" ball bearing. It works with the Park CT-4.2 or CT-4.To replace the chain tool pin, unscrew the cap, and pull out the old pin. Use care not to lose the ball bearing beneath the pin. Install the new pin and replace the cap.
I have to write about the CT-4.2 Master Chain Tool -- simply the best tool for replacing Campy Record chains -- what a gem!