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 ELK-SL1B is a weather resistant strobe light designed for easy attachment to ELK’s stainless steel speaker and siren units. The attractive SL1 features simple 12 Volts DC two-wire hookup, low current draw, and compatibility with virtually all 12 volt control panels (including pulsing alarm outputs). The ELK-SL1 is molded from virtually indestructible polycarbonate, such as Lexan. Kit IncludesELK-150RT Stainless Steel Enclosure Installer Friendly, easy to Mount Sealed Reed Tamper Switches at single bolt closure and at rear of cabinet No Rust, no mess Exterior / Interior use Compact, less Noticeable ELK-SL1B Strobe Light Interior or exterior use Operating Voltage: 12 VDC Works with steady or pulsing alarm outputs Fits ELK Stainless Steel Enclosed Speaker/Sirens Easy to Install, simple 2 Wire Hookup