Yes they are B-Squares, BUT thet are for 6" BBLs ONLY. They replace the front and rear sight. Its a full length rib mount. Last I checked prices Midway USA was cheaper than Natchez, but it MIGHT have changed. If you have less than a 6" bbl then you can still get a mount for it, but a gunsmith will have to drill and tap the gun for you.
Brian M.