These Brass Hex Nipples, as the name suggests as joiners for two same sized Brass pipes or fittings. These nipples are having barbs on both the side, so that they can hold the pipe fittings tightly, preventing them from slipping or any kind of leakage. These are available in different sizes, as for 3/4″, 1″, 1-1/2″, 2″, 2-1/2″, 3″. These all the sizes are of the inner diameter only. We are now working on different other products too, made up of brass, aluminum etc. P.S.: We have been asked to use Zinc fittings or as in for our Brass Sprinklers, so as to reduce the pricing by many of our buyers, but we deny as for the quality constrain. These all of our products are used in Irrigation and other water distribution activities, and using zinc may poison them, which is bad. In order to just earn easy money, we will never indulge in such practices, and all those mailing us to do so, please try to understand.