This adapter ring is mainly used for connecting the "Pentax PK K Mount Lens" to "cameras with Sony NEX E Mount", easy and smooth to install, remove and operate lens. Features: This lens mount adapter ring is mainly used for connecting the "Pentax PK K Mount Lens" to "cameras with Sony NEX E Mount". Suitable for Sony NEX E Mount camera, such as for Sony NEX-3 NEX-3C NEX-3N NEX-5 NEX-5C NEX-5N NEX-5R NEX-5T NEX-6 NEX-7 etc. Completely manual control, manual focus and manual exposure. There is no electrical connection on the ring so diaphragm control of the lens is set manually. It can focus to infinity. Easy and smooth to install, remove and operate lens. Equipped with lock and stop pin. Made of high-quality material, durable for long time use. Specifications: Material: Metal Compatible lens: for Pentax PK K Mount Lens Compatible camera: for Sony NEX E Mount Camera Item size: Approx. 6 * 6 * 3.2cm / 2.4 * 2.4 * 1.3in Item weight: Approx. 98g / 3.4oz Package size: Approx. 6.8 * 6.8 * 3.5cm / 2.7 * 2.7 * 1.4in Package weight: Approx. 105g / 3.7oz Package List: 1 * Adapter Ring