One 8 inch polypropylene cone with butyl rubber surround and one 1 inch polypropylene balanced dome tweeter with FerroFluid. Integrated backcan with 25/70.7/100-volt tap settings with transformer bypass position for ease of ordering, stocking and installation. Snap Cam four-point, spring-loaded mounting system for rapid installation. Quick-release mechanism for easy servicing. Ceramic input terminal accepts up to 10 gauge plenum rated signal wire and includes thermal fuse. Suitable for use in voice alarm applications subject to EU regulations EN60849 and BS5839-8. Adaptable to ceiling thicknesses ranging from 12.70 mm (0.5 in.) to 19.05 mm (0.75 in.). UL 1480 (UEAY) and 2043 approved. Included accessories: tile bridge, UL-listed flex conduit clamp, paint shield.