The Series 2000 Pro Flow 120 Degree Hose Ends differ from the Series 3000 Hose Ends in the fact that they feature the “single nipple” method of hose attachment. With the “single nipple” style, the socket draws the hose over a long tapered single nipple. The sealing feature is the crush of the hose between the inside of the socket and the outside of the nipple. With this style of hose end, reusing it is a breeze. There is no sliver of cut hose to remove before reinstalling the hose end on a new piece of hose.