Weather-resistant, vandal-resistant aluminum build ensures defense against moisture, dampness, and rust. 25/70V transformer equipped with a screwdriver-adjustable, 7-position watt/impedance selector switch. Easy, universal-mounting bracket adjustable in both horizontal and vertical planes, featuring banding slots for beam or pillar installation. Complies with or surpasses UL Listed criteria for audible signal devices. Certifications include UL Standard 1480Speakers for Fire Protective Signaling Systems, California State Fire Marshal (CSFM) Title 19