I tried to use this mount to put a
TLR-2 light/laser combo on an 870. For a targeting laser, it's a no go. The unit is very flexible and would not hold zero. If you have an extended mag tube on you 870 then the Streamlight 12ga Mag Tube Rail Tactical Mount 69901 is the ticket. If you were going to use it to mount a light only an had no other options, I suppose it would be a nominal solution.
Pros: If you don't have an extended mag tube, this is your ticket
Cons: Quite flexible
This review was written in the old system and had content requirements that are different than reviews written today.