Vivitar Series 1 Rare 500mm f6.3 DX Telephoto Mirror Lens for M42 [EXC]

This is a nice lightweight telephoto mirror lens with top shelf optics. I cannot find many examples of it online. Back in the day, Vivitar Series 1 was as good as if not better than the name brand stuff. Most of the 500mm mirror lenses that I see at f8, this one is about a half stop faster at f6.3. This lens has a universal T mount. It comes with an M42 screw mount. It would be an excellent addition to a classic M42 kit or adapted to mirrorless. It is in excellent condition with light wear and works perfectly. The glass is clean and scratch-free with no haze, fungus or other problems. The focus is a little dry but turns easily. Lens caps are included. This is a nice one. SKU: 231212-18