Designed for indoor and outdoor applications where voice and visual alerting is required in high ambient noise environments, Wheelock cluster speakers are available with 2, 3, or 4 speakers for wide-area coverage and a variety of strobe options, including clear and colored lens. The pre-assembled cluster speakers are supplied with STH-15SR horns and one RSS-24MCCH strobes or one DC-MAX strobe, depending on model number. All horns and strobes are mounted to a NEMA 1 steel enclosure and come fully assembled. Mounting options include wall, ceiling or roof. Approvals include UL Standard 1480 (horns), UL 1971 (RSS clear lens strobes), UL Standard 1638 (RSS colored lens strobes/DC-MAX strobe).