WHY CHOOSE ND FILTER: Using high quality optical glass, lightweight aluminum filter frame, high light transmittance. Main effect of this ND filter is to reduce amount of light into camera, prolong exposure time, can effectively reduce shutter speed. | 2 IN 1 USE: The lens filter is suitable for almost all the smartphones with the clip design. Without the clip, it can also work with the DSLR cameras with 37mm lens thread. Adopts 37mm lens mobile phone clip designed, large strength clamping, can used to install any other 37mm filter. | ADJUSTABLE ND FILTER: ND2 to 400 ND filter, 1 to 9 gears reduce light. Reduce the amount of light reaching the film without affecting the color. It can adjust exposure gear freely according to needs, bring more exposure options to your photography. | WIDE APPLICATION: Neutral density lens filter is suitable for shooting water flow, traffic flow, ocean, clouds, human stream and other moving photography. Also is great for removing unwanted reflections from non metallic surfaces and increase contrast and color saturation. | SERVICE GUARANTEE: We have a professional customer service team. Please contact customer service in time if you have any questions, we will solve them as soon as possible. Hope you have a good shopping experience. Please allow a slight error due to manual measurement.