This fitting is perfect for those customers trying to get gas out of their 100lb cylinder with the CGA 555 valve that want to go directly to their 1/2" or 3/8" hose.Can be adapted to 1/2" M JIC with SS304083 or 1/2" M SAE with SS304077. Or go down to 3/8" M SAE with SS04053 Or 3/8" MJIC with SS304074.