The Speed Booster XL 0.64x Adapter for Full-Frame Canon EF-Mount Lens to Select Micro Four Thirds-Mount Cameras from Metabones allows a full-frame Canon EF-mount lens to be mounted onto a Micro Four Thirds-mount camera. While doing so, the adapter's optics help to maximize the connected lens's apparent angle of view while providing a 1.3-stop increase for the camera over the lens's aperture range.

If a lens intended for 35mm film or similarly-sized "full frame" camera sensors is connected to a camera with a Micro Four Thirds-sized sensor, it would project an image larger than the Micro Four Thirds sensor was built to accept. Able to capture only the center portion of the projected image, the effective angle of view of the lens would be narrowed, creating an in-camera "crop factor". The Speed Booster XL 0.64x Adapter for Full-Frame Canon EF-Mount Lens to Select Micro Four Thirds-Mount Cameras condenses the light from a lens designed for 35mm film or "full frame" camera sensors and projects it onto a Micro Four Thirds sensor. This allows a Micro Four Thirds sensor to utilize all of the light gathered by a connected lens, which effectively reduces the crop factor while making available to the sensor an additional 1.3 stops of light for each of the lens's f/stop settings.

This adapter is constructed from aluminum alloy for durability while minimizing weight and its mounting rings are made with brass to further prevent wear-and-tear. Inside are six lens elements that are designed to provide optical clarity as well as color fidelity, and a detachable tripod foot is included that features a 3/8" threads as well as compatibility with Arca-Swiss tripod heads.

The Speed Booster XL 0.64x Adapter for Full-Frame Canon EF-Mount Lens to Select Micro Four Thirds-Mount Cameras supports electronic communication between an attached camera and lens. Although the attached lens must be manually focused while using the adapter, aperture settings can be can be controlled from the camera.

This adapter can be mounted onto the Panasonic DMC-GH4, GH3, G3, G5, G6, G10, GF3, GF5, GF6, and GX1 Mirrorless Micro Four Thirds Digital Cameras; the Olympus PEN E-PL7 Mirrorless Micro Four Thirds Digital Camera; the Blackmagic Cinema Camera with Micro Four Thirds mount; and the Blackmagic Pocket Cinema Camera.