jbohio I called Keen Sight about five weeks ago and ask Vicki for some help . My problem was (WAS) my comb was to high and I had to see rib . My POA was alittle low and seeing rib did help that but I like looking down the rib . Vicki sent me an Add-on rib 1/4 inch high and down alittle in front . It looks good on the barrel and shoot well for me . A new barrel for my gun was $2750.00 the add-on rib was $210.00 a no brainer .