CP+ 2019: Hands-on with the Sigma MC-21 SA / EF to L-mount adapter:
https://www.dpreview.com/articles/3970341505/hands-on-with-the-sigma-mc-21-sa-ef-to-l-mount-adapter
https://www.dpreview.com/articles/3970341505/hands-on-with-the-sigma-mc-21-sa-ef-to-l-mount-adapter