Optics Planet has the Meprolight Bead sight for Mossbergs on sale with a big 33% off...$39 marked down to $26. I just ordered one...to good to pass up.
http://www.opticsplanet.com/meprolight-tru-dot-shotgun-night-sights-for-mossberg-shotguns.html
Have at it!
http://www.opticsplanet.com/meprolight-tru-dot-shotgun-night-sights-for-mossberg-shotguns.html
Have at it!