I listened to the lennox infomercial on their web page, it said little, talked about a 2 “STAGE) air con system.

are they talking about a 2 stage condenser  fan or a 2 stage compressor?? they were real vague about it.

I thought 2 stage compressors were still ,  how shall I say it ?    Unproven??

does trane/amer std make a 2 stage home air conditioner ? like in 3  or 4 ton size?