Fotodiox Pro Lens Mount Double Adapter - Rollei 6000 (Rolleiflex) Series and Canon EOS (EF / EF-S) D/SLR Lenses to Micro Four Thirds (MFT, M4/3) Mount Mirrorless Camera Body with Built-in De-Clicked Aperture Iris Lens Mount_Olympus Pen-F You can easily find B4

You can easily find B4 lenses on KEH

Mounts Konica Auto-Reflex (AR) SLR Lenses to Micro Four Thirds (MFT) mount mirrorless cameras

it is NOT suitable for Pentax Takumar lens (Fotodiox V

Lens Mount: Exakta

Mounts Olympus Zuiko (OM) 35mm SLR Lenses to Fujifilm X-series mirrorless cameras

Fotodiox Pro Lens Mount Double Adapter - Rollei 6000 (Rolleiflex) Series and Canon EOS (EF / EF-S) D/SLR Lenses to Micro Four Thirds (MFT, M4/3) Mount Mirrorless Camera Body with Built-in De-Clicked Aperture Iris Lens Mount_Olympus Pen-F You can easily find B4Features: Double adapter mounts Rollei 6000 (Rolleiflex) Series & Canon EOS (EF EF S) D SLR Lenses to Micro Four Thirds (MFT) mount mirrorless cameras; infinity focus or beyond allowed Integrated adjustable iris to allow some control over depth of field (** Will also produce sever vignetting ** ) Integrated de clicked aperture iris for incoming light adjustment Enhanced craftsmanship and high tolerance construction for demanding professionals Precise