Very nice set of MX3 Special 31 1/2 inch over/under Seitz barrels. These will fit any square mono block receiver. They WILL NOT fit round mono block receivers like MX3, MX5, MX7, etc. If you're unsure please contact me and I'll help. Bottom barrel .737 bore .715 choke .022 restriction, Seitz ported Top barrel .737 bore .703 choke. 034 restriction, Seitz ported Barrels are marked 1.610Kgi but are probably slightly light due to Seitz's back boring. Overall a very nice set of barrels with some bluing wear at the forest. $2750 plus $30 to ship.