The MP120KA features an easy plug in design and has been fitted with a power supply that converts the 120VAC to nominal 24V FWR. The mounting plate may be used for indoor (flush mount) or outdoor applications. For indoor applications, complete field wiring and attach the mounting plate to a four inch square back box. Attach the horn, strobe or horn/strobe, chime or chime/strobe to the mounting plate by inserting the product’s tabs in the mounting plate’s grooves. The device will rotate into position, locking the product’s pins into the mounting plate’s terminals. The device will temporarily hold in place with a catch until it is secured with a captured mounting screw. For outdoor applications, the MP120KA must be installed using the SpectrAlert Advance weatherproof back box and outdoor listed K-series models.