I had Vicki Keen at www.keensights.com do one for my K-80. She's very knowledgable and was able to give me dimensions that worked. I sent the barrel to her and had it installed. Outstanding service and outstanding to work with. Michael
The ribs by Hydeal are easy to install yourself,, and come in 4 heights,I have a supply of them and for an 870 a 28" is what you need, 5/16 width, you decide the height. up to 5/8" hi. You need to have an adjustable comb, or build it up to match the rib. These are good looking and when installed properly will stay in place. They come with adhesive tape installed on the rib, just warm both pieces and place it carefully! 866-868-9410 Paul
Several places can do a nice job with add on ribs but Vicki Keen at www.keensights.com supports this site and her work is very good. Using this site is fun and I suggest that we support the businesses that support our fun.