Fits the following:

Armscor/Rock Island Armory VR82 20ga
Benelli 20ga Nova Pump
Beretta 20ga 3901
Beretta 20ga 471 Silver Hawk
Beretta 20ga AL391 Teknys Gold, and Gold King Ranch
Beretta 20ga AL391 Urika 2 Gold, X-TRA, Youth, Sporting
Beretta 20ga Silver Pigeon S King Ranch and IV King Ranch
BSA 20ga
Charles Daly 20ga Model 106
Charles Daly 20ga S/S Field II
Franchi 20ga
Franchi 20ga 48AL
Franchi 20ga Affinity 3
Franchi 20ga Fenice
Franchi 20ga Instinct O/U
Mossberg 20ga SA-20
Savage/Stevens 20ga 512 Gold Wing
Smith and Wesson 20ga 1000 (Current version starting in 2007, made in Turkey)
Stoeger 20ga M3020
Traditions 20ga Semi Auto
TriStar 20ga Cobra
TriStar 20ga Raptor
TriStar 20ga Viper
Weatherby 20ga PA 459