The TTArtisan 250mm f5.6 M42 Mount Reflex lens is a compact, manual-focus telephoto lens with a catadioptric design. Its unique metal mirror construction ensures up to 98% reflectivity, delivering sharp images with minimal chromatic aberration. The distinctive “doughnut” bokeh adds creativity to portraits and floral photography. Weighing just 380g, it's compatible with M42 and other mounts via adapters.