These STROBES and HORN STROBES are tamperproof with selectable candela options of 15, 30, 75, 95, 115, and 150. They come with a Super-Slide® Bracket and Checkmate® Instant Voltage Verification. The horns feature a continuous or sync temporal three in 2400 Hz and mechanical tone. Ceiling mountable. 24 VDC. UL listed.