USAGE: Commonly used to convert the thread size of your lens to the thread size of many other accessories, such as filters, lens hoods, lens converters, or flashes for better effect; Compatible with for , , Camera, and so on. HOW TO USE: The first number indicates the lens thread size, and the second number is the filter size; Step-up rings provide a way to mount a larger diameter filter or accessory onto a smaller lens. Step-down rings work in exactly the same way but instead provide a way to attach smaller accessories and filters to larger lenses; They screw easily onto the front of the lens with a tight fit; Very easy to install. ULTRA-LIGHTWEIGHT: Designed to be ultra-thin and lightweight, keeping filters close to the lens. Corrosion-resistant metal construction makes it popular for outdoor photography; Durable and well-finished surface; Tight fit and no wobbling. Color: Black Material: Aluminum Alloy Package Contents: 18 x Step-up Rings (including: 37-49, 49-52, 52-55, 55-58, 58-62, 62-67, 67-72, 72-77, 77-82mm) 18 x Step-down Rings (including: 49-37, 52-49, 58-55, 55-52, 62-58, 67-62, 72-67, 77-72, 82-77mm) Only the above package content is included; other products are not. Note: Light reflection and different displays may cause the color of the item in the picture to differ slightly from the real item. The allowed measurement error is +/- 1-3 cm.