This is the way to connect fittings to your pressure tank. You get (2) combination 3/4 female and 1" male ports for in and out, (2) 1/2" holes, (2) 1/4" holes and a 1" male thread for connecting under most pressure tanks. This can easily be bushed into a 1-1/4" hole found on bigger tanks. The union makes installation very easy and subsequent tank service particularly easy.