(Telephoto Lens with Reflective Optics) The SZX SUPER TELE 15.7 inches (400 mm) mirror lens has a focal length of 15.7 inches (400 mm) on a compact body | Weighs only 12.8 oz (355 g). Ultra Lightweight Design (Excluding Mount Part) For telephoto lenses that are not uncommon to exceed 1.2 lbs (1 kg), the "Super Tele 15.7 inches (400 mm) F8 Reflex MF" is lightweight at only 12.8 oz (355 g). You get rid of the worries of "Telephoto lenses are heavy and don't want to take them with you..." | (Reflective Optics with a distinctive ring boke) Uses a unique reflective optic system that uses a "ring boke" that creates a hole in the center of a point light source for a unique and fantastic depiction | (Convert to another mount with T-Mount Adapter II) Both the lens and extender are T-mounted. The "T-Mount Adapter" is used to attach to the camera, so if you have multiple cameras with multiple mounts, you can choose the "T-Mount Adapter" to give you the freedom to replace multiple mounts. (The electronic contacts are not equipped. ) | [Product Specifications] Mirror Lens: Focal Length: 15.7 inches (400 mm) / Brightness: F8 (fixed) / Lens Configuration: 6 pieces in 2 groups / Angle of View: 6° 8' (35mm format) / Filter Diameter: 2.7 inches (67 mm) (front side) / Minimum Focus Method: Manual Focus (Front Ball Extruded Size: 4.4 x Φ 2.9 inches (74 mm) (mirrorless mount), 3.2 inches (82 mm) x 2.9 inches (74 mm) (SLR mount); Weight: 19.3 oz (545 g) (mirrorless mount); 17.6 oz (500 g) (SLR mount)