The Meike EFTR 0.71X Speedbooster lens adapter enables seamless compatibility between cameras with a Canon RF mount and lenses with an EF mount. This optical adapter features a 0.71X focal length reduction factor, which increases the lens's light-gathering ability by about a full stop, while maintaining full electronic communication between the camera and lens. The precision housing, made from aluminum alloy, measures approximately 45 mm in length with a diameter of 72 mm and weighs around 185 grams. The adapter retains autofocus functionality, image stabilization, and electronic aperture control while converting the focal length and maximum aperture of the lens. The optical system uses high-quality glass elements with multi-coating to minimize stray light, ghosting, and chromatic aberration. When used with compatible weather-sealed equipment, the adapter maintains its weather-resistant construction. The focal length reduction effect provides a wider field of view and a brighter viewfinder image while maintaining edge-to-edge sharpness across the entire image field. It is compatible with Canon RF mount mirrorless cameras and most Canon EF and EF-S mount lenses, excluding certain super telephoto lenses that require additional support. The adapter does not require an external power source and operates entirely through the camera's electronic communication system. The attachment and release mechanisms have precise tolerances for a secure lens fit without play or wobble. This optical adapter serves photographers and videographers who wish to utilize existing EF mount lens collections on modern RF mount camera systems while enhancing optical performance characteristics.