REMA TIP TOP's CH3 valve cores are designed to work with TR-218 and TR-618 fast flow valve stems. This bag of 10 REMA TIP TOP No. 218-LB CH-3 valve core housings extend the life of your existing valve stem and keep you from having to replace existing valve stems. These valve cores fit all Fast Flow air/liquid valve stems except for Super Large Bore valve stems. Removing the CH-3 valve core allows you to inflate tires quicker and add liquid to a tire when needed.