This hose fitting is included in the Hayward above ground skimmer packages. This is designed to thread into the wall fitting using the 1-1/2″ male threads on the front. The opposite side is designed to fit a 1-1/2″ inside diameter pool filter hose..(1-1/2″ male threads actually measure about 1-7/8″ diameter”)

Dimensions and Specifications Thread diameter :1-7/8″ (1-1/2″ MPT) Length:3-3/8″ Smooth end diameter:1-1/2″ “SP-1091-Z-4” is molded on the side