Magazine Extension for 90 Series. Made of billet aluminum, this magazine extension is designed to increase the magazine capacity by 2 rounds (if 9mm caliber, if .40 caliber the capacity increases by 1 round), it features the ''Beretta'' logo on the left side. Specifications for Beretta 90 Series 9mm +2 Rounds Magazine Extension: Manufacturer: Beretta Color: Black Magazine Capacity: 2 Round Caliber: 9mm Luger Gun Make: Beretta Gun Model: Beretta 90 Package Contents: Beretta 90 Series 9mm +2 Rounds Magazine Extension What firearm models does the manufacturer say Beretta 90 Series 9mm +2 Rounds Magazine Extension is compatible with? The manufacturer suggests that Beretta 90 Series 9mm +2 Rounds Magazine Extension is compatible with Beretta 90