Both 12 and 16 inch lengths
The 12 inch barrel length
American Tactical Imports offer the entire line of Bates & Dittus (B&D) products.
B&D brings exciting products to the industry. B&D specializes in 37 mm launchers of several varieties including a pistol configuration (SML-37) and the new under barrel launcher (UBL-37). In January, the company made a formal announcement that gave ATI exclusive worldwide rights to distribute all B&D products. Now, these products are stocked and ready for shipment through ATI.
B&D launchers are made of 6061 aircraft grade aluminum and 4140 hardened steel. They can handle 37mm ammunition including flares, smoke and pyrotechnic rounds for civilian use and batons, CS gas, rubber pellets and other less-than-lethal options for law enforcement and military.
The Extreme Duty Top Break, or ExD-37, caters to law enforcement and military and is intended to function consistently with training tactics; it is DAO with an internal hammer and approximately a 15 pound trigger pull and available in 12-inch and 16-inch lengths, both with a custom aluminum vertical foregrip. (B&DE12CSV and B&DE16CSV)