This PVC Drain Pan Fitting is the "go to" fitting when it comes to washer drain pan installations. It is designed with a 1 inch diameter through drain for use with a 1 inch NPT pipe. The PVC Fitting will install with the threaded end protruding into the Drain Pan Interior and the coupling end extended out of the pan to be fitted with a 1 inch NPT PVC pipe. Using proper adapters may also allow the fitting to be used with other sized drain piping. This fitting works perfectly with our stock drain pans. Required hole size for this fitting is 1.38".