Prime / alpha-e / 12mm F2.8 ED AS NCS Fisheye
A Samyang manual-focus fisheye lens for full-frame cameras, offering an ultra-wide 12mm angle of view and an F2.8 aperture.
It is part of the “12mm F2.8 ED AS NCS Fisheye” series, which uses ED glass and NCS coating.
The series is available for multiple mounts, but this product’s mount cannot be identified from the name alone.