This is our most popular upgrade for our 2 bulb system. The FreshAire UV Air Handler (AHU) Mount Kit # TUV-200DDIP-Z adds several nice options to our standard kit. First of all we upgrade you to 2 each, two year bulbs for twice the run time longevity before replacement, secondly we add a 110 Volt plug, which is removed for 110V, 220V or 260V hardwire applications, lastly we add two magnetic mounts enabling the easiest mounting for the 2, two year lamps. More