Briley Shotgun Magazine Extension w/Picatinny Benelli/Breda Semi-Auto 12 Gauge +4 Rounds w/Sling Swivel Polished Black TSPA-51PSWPOL. The extension is made of tough 6061 aluminum. This allows the tube to have a large wall thickness to improve rigidity without compromising overall weight. The tube screws down on the magazine and locks the fore end in place. The extension is supplied with a magazine tube spring. Specifications for Briley Benelli/Breda Semi-Auto 12 Gauge +4 Rounds Shotgun Magazine Extension Picatinny w/Sling Swivel: Manufacturer: Briley Color: Black Finish: Polished Fabric/Material: 6061 Aluminum Magazine Capacity: 4 Round Gun Make: Breda Benelli Gun Model: Benelli Super Black Eagle III Benelli Super Black Eagle II 12 Gauge Benelli Super Black Eagle 12 Gauge Benelli M1 Benelli M2 Features of Briley Benelli/Breda Semi-Auto 12 Gauge +4 Rounds Shotgun Magazine Extension Picatinny w/Sling Swivel Benelli M1 M2 Super Black Eagle I II & III and Super 90 Breda Package Contents: Briley Benelli/Breda Semi-Auto 12 Gauge +4 Rounds Shotgun Magazine Extension Picatinny w/Sling Swivel What firearm models does the manufacturer say Briley Benelli/Breda Semi-Auto 12 Gauge +4 Rounds Shotgun Magazine Extension Picatinny w/Sling Swivel is compatible with? The manufacturer suggests that Briley Benelli/Breda Semi-Auto 12 Gauge +4 Rounds Shotgun Magazine Extension Picatinny w/Sling Swivel is compatible with Benelli M2 Benelli M1 Benelli Super Black Eagle 12 Gauge Benelli Super Black Eagle II 12 Gauge Benelli Super Black Eagle IIIBriley TSPA-51PSWPOL: Shotgun Magazine Extension w/Picatinny Benelli/Breda Semi-Auto 12 Gauge +4 Rounds w/Sling Swivel Polished Black