Briley Modular shot Shotgun Magazine Extension with Barrel Clamp (+4 or +6 Rounds) 12 Gauge (VersaMax and V3)

Options:
Price: $134.95
This extension allows you to increase the ammunition capacity of the shotgun. 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.

Fits:
Remington VersaMax

Note: 
The clamp spacer position on the extension is good for any barrel 24 inches or longer. Shorter barrels will require custom positioning of the spacer.