In this section you will find fittings where at least one of the connections is 1 1/2" Street/Spigot which means this side would glue inside of another fitting and would measure 17/8" Outside Diameter or 1 1/2" Slip which would allow a 1 1/2" pipe or fitting to glue inside of the Slip Fitting and would measure 1 7/8" Inside Diameter.