I just really like the design. Simple and functional. It looks like it should fire something more powerful than the 7.62x25mm Tokarev.

SinoDefense:

The Type 79 submachine gun is more or less patterned after the Type 56 (AK-47) assault rifle. It uses gas-operated, rotary bolt action with short stroke gas piston located above barrel. The bolt group and fire mode/safety switch are similar to those of the Type 56 rifle. The barrel, receiver, pistol grip, magazine and shoulder stock are all made from stamped steel. The weapon fires 7.62 X 25mm pistol cartridge in either single or fully automatic mode. Ammunitions are fed from a straight box magazine that holds 20 rounds. Shoulder stock folds up and forward when not in use.

Hat Tip: MP.net