Best to use a plumbing cleaner then pipe cement to assemble. Pipe work pushes inside this part at the female end. Comes complete with a 2" o'ring.
This is a fantastic product bought in by Waterway recently with in the last couple of years. Before this design came about plumbing from the top of the pump in tight spaces was a nightmare now Waterway have combined a 2 inch 45' elbow with the union nut all in one. Not only does it reduce the overall height but also increases flow directly out from the top of the pump