Multi Layer Nano Coating Process: Lens has waterproof, oilproof, anti fouling, and anti scratch properties to protect the lens from dust and scratches. Material: Aluminum Alloy + Optical Glass. Applicable Models: There are three kinds of interfaces: 40.5mm/1.6in, 43mm/1.7in, 46mm/1.8in, 49mm/1.9in, suitable for 40.5mm, 43mm, 46mm, 49mm interface lens.
eBay