Key Features: Focal Length: 300mm, providing a long telephoto reach. Maximum Aperture: f/5.6, suitable for good light gathering and background blur. Mount Type: M42 screw mount, compatible with a wide range of vintage and modern cameras via adapters. Optics: Typically includes multi-coated or single-coated optics for reducing lens flare and improving contrast. Focus Type: Manual focus for precise control over focusing distance. Build Quality: Generally sturdy construction with metal barrel and focusing ring. Aperture Range: Typically ranges from f/5.6 to f/22, offering flexibility in exposure control. Compatibility: Compatible with various M42 mount cameras, including film and digital cameras with appropriate adapters. Condition: As it is a vintage lens, the condition can vary. It may show signs of use such as minor scratches or wear on the barrel, but optically it should be in good condition unless otherwise specified.