The Edwards Catalog Series B-8526 and B-N-8546 (single projector, Figure 1) and B-N-8590 and B-8599 (double projector, Figure 2) units are weatherproof Adaptahorns in NEMA 4X Enclosures. The sound mechanism of each signal starts and stops instantly with current impulse. Both the single and double projector models are designed for use where a loud distinctive signal is needed, both indoors and outdoors. The Catalog Series B-N- 8546 and B-N-8590 Adaptahorns are both UL listed and CSA certified and use a NEMA 4X enclosure.