Fun little guns. Built like a tank!!
Everyone sells them: South Summit, Compasseco, Best Air, Fun Supply, Sportsman's Guide (only $49.97), etc.
I've had the early TS-45-2 of the current B3 "AK" and the B7 wood stock "normal" version. The XS-B3 AK folding stock version is much more fun then the B7. I need another one. I gave my old TS to my nephew and regret it. It had the barrel chopped to 10" and the forearm was a little different then....a great little shooter.
Plenty of info on these by doing a google search, or a search on various forums. Fun Supply has good info on them.
You can shoot 'em out of the box, or tune them up. Good plinkers and can be surprisingly accurate.
Jack