SelecTone Explosion-Proof 15 Watt Amplified Speaker, 24VAC/DC - Available in 24VAC/DC and 120/240VAC. Digital signal amplification. Cast copper free aluminum housing, spun aluminum projector. Built-in gain control, adjustable between 0 dBa to 110 dBa at 10 feet (0 dBa to 120 dBa at 1 meter). Fused input and output. Indoor/outdoor use. Type 4X, IP66 enclosure. CSFM Approved. UL and cUL Listed for Class I, Division 1, Groups B, C, and D & Class I, Division 2, Groups A, B, C, and D & Class II, Division 2, Groups F and G & Class III.