Vizelex Polar Throttle Fusion Smart AF Lens Adapter - Canon EOS EF (NOT EF-S) D/SLR Lens to Sony Alpha E-Mount Mirrorless Camera with Full Automated Functions and Built-in Circular Polarizing Filter

As far as I can tell, they can’t update the firmware on these, and they really do crash all the time and the aperture setting barely works etc. The polarization is fine, and handy especially if you have large or rotating front lenses, but the glass must be kept absolutely clean as it’s right next to the sensor. I wouldn’t pay full price but Amazon warehouse had this for over half off and I cleaned the glass and am happy enough.