FotodioxDLX Stretch Lens Mount Adapter - Contax/Yashica (CY) SLR Lens to Sony Alpha E-Mount Mirrorless Camera Body with Macro Focusing Helicoid and Magnetic Drop-in Filters

This is an awesome product. I've been using regular adaptors to mount Contax C/Y lenses on my A7ii. When I saw the "Stretch", I decided it would be nice to be able to get a little bit closer with some lenses.PROS: Well made and nicely finished. All metal and the Helicoid has a nice, smoothly damped feel. Not too tight, not too loose. Stays put but easily adjustable. The interior is matte black and "ribbed" to reduce internal reflections. The Stretch extends @16mm.CONS: It's heavy. About 1.5 to 2x heavier than a simple "dumb" adaptor. A little bulky - the knurled Helicoid ring is large.BONUS: Most adapted lenses focus "past" infinity. Adaptor designers do this on purpose to ensure that lenses will not stop BEFORE infinity. With the Stretch, I can dial in just a tiny bit of extension, which brings perfect infinity back to the focus ring's end stop! Worth the cost and weight alone.

It does the job for a Contax/Zeiss to Sony setup, but the fit seemed too tight for my comfort. I purchased the much more expensive Novoflex and it fits perfectly.