The ELK-1RT is a rugged 30 Watt, 8 Ohm speaker mounted in a tamper resistant, "No Rust" enclosure. It features two sealed reed tamper switches, one on the Back plate and one on the Front Cover. The stainless steel naturally reflects the mounting surface and blends easily with any residential or commercial building. Also available is the ELK-150RT with Built-in Siren or the ELK-SL1 Strobe Light that can be added to the enclosure by ordering separatly. The ELK-150RT is a self-contained Siren in a tampered "No Rust" stainless steel enclosure. It features two sealed reed tamper switches, one on the Back plate and one on the Front Cover. The switches are normally closed and pre-wired in series. The ELK-150RT can produce two distinct sounds from a single input trigger. The stainless steel exterior reflects the color of the mounting surface allowing the ELK-150RT to blend easily with any residential or commercial building. The ELK155RT provides pre-recorded voice and siren sounds.