Tamron 3X Aux Telephoto Lens w/ Leather Case & EdnaLite 558 Adapter

Hi. This auction is for a vintage Tamron 3x Aux Telephoto Lens. I buy and sell cameras but I have never seen one of these before and honestly don’t know anything about. That being said, I can tell you that it is in nice condition. The glass is clear, clean and scratch free. There is a little internal dust like you find in all vintage lenses. It focuses smoothly. It has a screw thread mount which I measured to be approximately 34mm. It comes with and Ednelite 558 step down ring which goes from approximately 34mm down to approximately 26mm. Also included is its original leather case. The case looks good but the zipper doesn’t zip around completely. If you know anything about this lens, please share it with me. Thank you.