I'm not sure what the question is referring to either, but We, (Electricians) as per the NEC are to only install equipment that is listed or labelled by a recognized lab. If it is made up of a series of individual components (each listed), such as a Hot Tub complete with Pump, blower, heater etc. it would have to be listed again as a 'Package' unit. Hope this is what you mean.

[Linked Image]
Bill

Bill