Shop › NORDIC +9 MXT TUBE 12GA BK NEEDS NUT NORDIC +9 MXT TUBE 12GA BK NEEDS NUT $68.95 Nordic Components MXT Magazine Extension Kit, +9, 12GA, Combines with Nordic MXT Extension Nuts to Form Complete Extension Kit, Shotgun-Specific Nut Required for Installation on Shotgun MXT-TBS-12-9 Quantity: Add To Cart Added! Nordic Components MXT Magazine Extension Kit, +9, 12GA, Combines with Nordic MXT Extension Nuts to Form Complete Extension Kit, Shotgun-Specific Nut Required for Installation on Shotgun MXT-TBS-12-9