I have an 870 with a Knight's RAS installed for sale. It is a single, full length, rail that extends about 1/2 way down the barrel. It also has a Scattergun Tech safety and mag extension. The sling plate has been modified so it can be mounted either on the right or left hand side. I can include an Armson OEG with a ring for $125 and an Insight Tech M-3 light for $90.
I will email pictures to people who are serious about purchasing.