The SMC Pentax-M 1:3.5 135mm lens is a high-quality telephoto lens designed specifically for Pentax cameras. With a maximum aperture of f/3.5, this lens is ideal for capturing detailed images with a shallow depth of field. Constructed with durable aluminum materials and manufactured in Japan, this lens offers excellent image quality and reliability. The manual focus feature allows for precise control over your shot, while the fixed focal length of 135mm provides stable and consistent results. Overall, this lens is a great addition to any photographer's arsenal, offering versatility and superior image quality for Pentax users.