The OMNITRONIC SPL-1 Indicator Rack Mount is an external warning indicator for the SPL-1 sound level limiter when operated in mute mode. Its three-colour LED indicators warn of impending muting when the level is exceeded, and up to three indicators can be connected in series. The unit is designed for 19-inch rack installation and occupies 1 U. It provides two RJ-45 female mounting connections and measures 48.3 cm wide, 13 cm deep and 4.45 cm high, with a weight of 1.30 kg.