THE UV-AIRE unit is designed to emit powerful UVC Band light rays, which sterilize and reduce airborne microorganisms as they pass through a heating or air conditioning system. IT IS INSTALLED in the main supply or return duct and operates continuously to automatically purify the air in the home 24 hours a day. UV-Aire Induct Model - 16" UVC 24V 24V PLUG-IN transformer included (no electrician required), compact design fits in tight spaces, built-in safety switch designed to light only inside the duct, and E-Z lamp replacement simple twist and lock. COMPACT design to fit into tight spaces, built in safety switch designed to light only inside the duct.