What is the relationship Sears and Carrier air-conditioners?

What is the relationship Sears and Carrier air-conditioners?
Neither company actually manufactures their product, that beingsaid all but only one company actualy does which in and of it'sself make it a good product considering their lack of tellent andresourses in product developement and testing.
Due to Sears Largest and Large national reach add in their massiveresources in both their design and research phycilities in DelawareCarrier found it much more cost effective to partner with Sears intheir combined efforts to design and test not only their ideas butthe out put of the compoinants from different manufacturers oftheir design elaments.
While Carrier offers 4 quality grades from low grade buildersquality to entry to Main line to premium, Sears only offers 3grades Entry ,Main Line and Premium. The only really differencesthat can be found are availability of premium 2 stage high qualitycompressors in the Kenmore Main line that is absant in the Carriermain line and only available in Carriers premuim line and theCarrier infinity air cleaner is only available when installed on acombined Carrier infinaty ac and heating systems. Other then thosedifferences Kenmore and Carrier are basicaly the same built by thesame manufactures on the same lines with idenical parts assembledby the very same assmebly lines.
The down side with Carrier is that unlike the Kenmore of which canonly be purchosed through Sear Home Services and installed by Searstrained and suppervised installers, Carriers are purchosed mainlyby whare merchandisers, so the time from manufacturing to actaulinstallation can very by years leaving the consumer to guess ifthey got the latest and greatest Carrier product as well to guessthe grade of the product.
Carrier is the inventor of Air conditioning while Sears was thefirst to actaully install them in homes.