Remington 870 Marine Magazine tube Coupling
So you lost it or put pliers on it and need a new one. Here it is, Remington Factory New Magazine Tube Coupling. In the future simply snug this down till it stops turning. A detent plunger engages the coupling and stops it from turning and over tightening it simply moves to the next divot and make it a bear to get off, then you grab the pliers and then you come here and buy another one. So install it right and you won't need another one. But still come here and with the money you save buy some other stuff.