StrionAir builds both commercial and residential air cleaners and was recently bought by Honeywell. The residential air cleaner model is sold through United Technology air conditioning equipment dealers and by the Honeywell distribution channels as TrueClean. Each brand has different sized housings and voltages. The Carrier/Bryant/ICP units fit their housings and come in both horizontal and upflow configurations. The Honeywell models are the sizes of their electronic filter housings, but deeper. I like the fact that you throw away the dirty filter. It makes servicing the unit much easier than the Trane model.
http://www.strion.com/technology.asp