This is a replacement valve used in Modine PA (and earlier) standing pilot heaters that have 120 volt controls (Pre 1980 models). Each valve comes setup for natural gas and includes kit to convert to propane. This is a RobertShaw gas valve with 3/4" x 3/4" openings and comes with 1/2" reducers bushings for the inlet and outlet so it can be used with any size unit. (Not for use with automatic pilot ignition systems)