The CYMA CM058 is a working airsoft replica of the BIZON PP-19 sub machine gun. This AEG uses a 8.4v stick battery (included). The undermounted cylindrical magazine is what makes this gun unique. Midcap magazine holds 170 rounds. Spare magazines are available.The gun is pretty nice feeling, solidly built, and very ergonomic for its size. Folding stock is metal and solid. Cyma did a great job making the CYMA BIZON PP-19 AEG model.