relevant necropost.....id never seen these sights before until this post, and thought they were cool. l have the 14" PRI tube on my 308 and its designed for dpms high while I have DPMS low. not a huge deal, but it leaves a 1/16" difference for mounting irons. I thought this could be a solution, but as noted, they are hard to find. on a random Ebay search last night I found a guy selling them for $15 shipped so I bought 2. he says they are legit. he bumped the price up to $20, but still seems like a good deal for a part that might come in handy down the road. just thought someone else might be interested. http://m.ebay.com/itm?itemId=261751470027