This speaker has a nominal power (RMS) of 250 Watts and a diameter of 12 inches. It does not have a box, which helps save space in the car cabin or trunk.
Passive subwoofers like this one do not have a built-in amplifier, so an external amplifier is required for them to function, which also determines the quality of sound reproduction.
In passive speakers, the phenomenon of overheating of the speaker and air during operation is not encountered due to the absence of an internal amplifier.