The American firm of Questar has a great reputation making telescopes, and still make among the world's finest. When Questar turned their considerable expertise to a camera lens, they came up with the Questar 700/8. This is a T mount lens, which means it can be adapted to virtually all 35mm SLRs just by changing the rear adapter. When tested by Modern Photography in the 1970's, the Questar 700/8 was rated the best mirror lens they had ever tested.
Own an American classic. In good condition cosmetically, excellent condition optically. Attach to tripod with 1/4 x 20 threads. $750 shipped to you, these regularly bring $1,000 on that other auction site.