Atlas Air Force AF7 Compressor ????

Can anyone comment on these compressors? I have been researching and am getting ready to buy and came across these at Greg Smith Equimpment, they appear to be the only line they carry. Any info would be appreciated. Here are some links, I like the 3 cylinder look.

http://www.gregsmithequipment.com/PhotoGallery.asp?ProductCode=ATAF7

http://www.gregsmithequipment.com/Atlas-Air-Force-AF6-p/ataf6.htm

Thanks,
PCW