Vented powered bass subwoofer enclosures. Power amplifier is forced-air cooled for maximum reliability. Internal line-level low-pass/high-pass crossover network. XLR/1/4" combo jack input. Two XLR high-pass outputs and one full-range XLR output. Ground lift switch to lift the ground wire shield. Full-coverage, heavy-duty perforated steel grille. Fully adjustable Kosmos® C for increased bass impact. Steel handles. Compact dimensions for an 18" subwoofer. Heavy-duty 18" premium woofer. Threaded pole mount with included speaker pole. 800 watts of peak available power. Large, heavy-duty locking caster with cushioned bearings. Polarity switch for subwoofer polarity reversal.