Hard to find anything else like it, but i had to shim to get tight - NcSTAR ShotGun Rails Bayonet Mount Remington 870

Same as others, I wanted to find a way to do 2 things. 1) I needed a front swivel mount to add a sling to my shotgun. Anything using the mag tube end cap would stick out too far in my Model 500A 20" where the mag tube is already flush with or actually a bit longer than my barrel. So, this tube mount gives me that since it comes with the ring to attach the swivel. 2) It also gives one the opportunity to mount a light to the standard picatinny rail which is nice. Though I tightened it all the way it was still loose on my shotgun. So, I had to shim it with some aluminum tape (the kind used to seal furnace ductwork) It is plenty sticky and compresses nicely. 3-4 pieces inside the mount and everything cinched down nicely with no movement. I did not really want/need the bayonet mount so I just shelved that. It looks nice is very functional and really inexpensive, so it all worked out for me. Other items just to allow me to attach the swivel were more expensive.