The Asahi Optical Co. Takumar 135mm f/2.5 Telephoto Manual Focus Lens is a high-quality lens designed for Pentax cameras, featuring a maximum aperture of f/2.5 for excellent low-light performance and shallow depth of field. With manual focus, photographers can achieve precise control over their images. The Takumar series is known for its superior optics and durability, making this lens a reliable choice for capturing stunning telephoto shots on Pentax K mount cameras.