The type of nozzle referred to here is known as a Medusa Nozzle. Medusa nozzles were introduced at the end of the 1980's by Aerotech, and are commonly seen on motors such as the 54mm diameter solid rocket motor reloads. The solid rocket propellant used in the late 1980's was low smoke propellant, with the White Lightning propellant formulation being introduced in 1989. The Medusa nozzle allowed the exhaust to be spread out and enabled a larger flame to be produced.

Initially, it may seem a bit strange having a single combustion chamber with multiple nozzles, and one may think that it degrades performance, however, the expansion ratio is not so critical for the level of performance required from these types of rocket motors, hence the reason the Medusa Nozzle is used.

Different numbers of nozzles are used depending on the propellant formulation, thus enabling single motor systems with different propellant formulations to operate more effectively at different thrust levels.