Rangers 20pcs Ultra-thin Camera Lens Filter Step-up Rings 26mm-82mm & Step-down Rings 82mm-26mm Set + PVC Pouch + Cleaning Cloth RA035 Made of a high quality aluminum alloy. Moisture-proof and dust-proof. Manufactured from a durable PVC faux leather material. Step up rings provide a way to fit a larger diameter filter or accessory onto a smaller lens. Step down rings work in the exact same way but instead provide a way to attach smaller accessories and filters to larger lenses.