I have a 3 shot extension (8.125") for a BPS. It is blued and new as I can tell. I picked it up at a show and was told it was for and 870, notta! Anyway, if anyone out there needs one and has a 870 extension (park would be great but not a must have) in trade that would be great. If not I will sell it for 25.00 +shipping. It has the spring and plug.