Only 7.4mm thickness ensures enhanced friction during rotation, making it easy to install and remove lenses and accessories With adjustable light reduction and 1-9 stops of 360 degree rotation for accurate dimming settings, this filter is for scenarios. (Note: The biggest stop can cause a pattern effect commonly known as x" Filter 37mm/40.5mm/43mm/46mm/49mm/52mm/55mm/58mm/62mm/67mm/72mm/77mm/82mm optional, please choose the size you need. Please check your camera's lens thread size before ordering Treated with an oxidized sandblasting process, this filter prevents unwanted light and minimizes unnecessary reflections Made from optical glass with 8 multi-layer coatings, this filter reduces reflections and ensures superior images