Carlson's Choke Tubes Shotgun Magazine Extension Assembly Benelli M1/M2/Super Black Eagle I/II/III 10-Round Black. These choke tubes feature a strong mag extension spring a built-in anti-rotation feature and knurled on the end to easily slip into the shotgun magazine tube. With these features plus a strong mag extension spring these chokes are able to extend 10-shot capacity for your shotgun. Don't let your favorite shotgun choke do all the work for you. Put a Carlson's Choke Tubes Magazine Extension quickly and easily onto your favorite shotgun. Specifications for Carlson's Choke Tubes Benelli Shotgun Magazine Extension Assembly: Manufacturer: Carlson's Choke Tubes Color: Black Finish: Black Magazine Capacity: 10 Round Gun Model: Benelli M1 Benelli Black Eagle Benelli M2 Condition: New Country of Origin: USA Features of Carlson's Choke Tubes Benelli Shotgun Magazine Extension Assembly Ben M1M2 SBE Mag Ext 10 Shot Package Contents: Carlson's Choke Tubes Benelli Shotgun Magazine Extension Assembly barrel clamp plus & spring What firearm models does the manufacturer say Carlson's Choke Tubes Benelli Shotgun Magazine Extension Assembly is compatible with? The manufacturer says that Carlson's Choke Tubes Benelli Shotgun Magazine Extension Assembly is compatible with Benelli M2 Benelli Black Eagle Benelli M1Carlson's Choke Tubes 04518: Shotgun Magazine Extension Assembly Benelli M1/M2/Super Black Eagle I/II/III 10-Round Black