Base with extra large mounting slots facilitates use with a wide variety of back boxes and other electrical accessories. Designed for back entry for recess supply wiring. Compatible to all sounder beacon (voice) devices (FDS224-R, FDS225-R, FDS226-Rx, FDS227-Rx, FDS227-Rx-C). Place for auxiliary terminals 2x DBZ1190-AA and 2x DBZ1190-AB.