Magazine tube nut for attaching Nordic Components extensions. Manufactured from aluminum billet and anodized matte black. Model specific Benelli: Nova/SuperNova, Beretta: 1301/391 Xtrema/ 391 Xtrema II/Tx4/ A400/A400 Xtreme (not A400 Xplor or Xcel), CZ: 712, 912, Weatherby SA-0