The Caruba Reverse Ring Nikon AI 49mm is a practical lens filter adapter specifically designed for Nikon cameras. With a diameter of 49 millimeters, this adapter allows for reverse mounting of lenses, providing a creative way to engage in macro photography. By using the reverse ring, photographers can reverse the focal length and focus of the lens to create stunning close-ups of small subjects. The adapter is designed with both an outer and inner size of 49 millimeters, ensuring easy and secure attachment to the lens. The construction of the ring is robust and durable, allowing for reliable use over extended periods. The reverse ring is an essential accessory for photographers looking to expand their creative possibilities and enhance the detail in their images.