This replacement elbow fixes the problem with the old style (grey colored) elbow leaking from the built in vacuum breaker. The threads are 3/4″ MIP, the other end inserts into the valve and secured with a clip. This replacement part includes the O-ring for the non threaded end, but does not include the retainer clip. This part does not include the DLFC (the colored part inserted into the non threaded end. You must remove the DLFC from your old drain elbow and insert it into the replacement part before connecting it to the valve body or your softener will not work properly. If you do not have the original DLFC contact us and we will help you get the correct size for your softener or filter.