Works with 870's - LaserLyte Shotgun Tri-Rail Mounting System Magazine Tube ADP-TRIR-140

It will fit on 870's with the factory extensions. The rail area is small but usefull, so be aware of the size of light mounts you use. You can also off set the rails at the lower 45 degree placements instead of 1 vertical and 2 horizontal. The only downside is you have to remove all accessories and the rail to remove the mag tube for any gun cleaning or maintenance. A surefire dedicated forend is easier to use but at this price the laserlyte trirail gives you more options and even with say an Olight M21 and mount you are less than half the cost with 4 times the lumen output. I should know I have an LED surefire front end on another 870 and I would recommend the setup over the surefire for HD work.
Pros: Sturdy-easy to use
Cons: Limited rail space, removal

This review was written in the old system and had content requirements that are different than reviews written today.