K&F Concept 49mm Variable ND2-400 Lens Filter, D Series. This ultra-thin filter is designed for photographers seeking versatile light control and superior image quality. Features: * Material: Crafted from top-tier Japanese optical glass with double-sided 24-layer enhanced coating. * Optical Performance: Reduces surface reflections and prevents glare during prolonged exposures, ensuring impeccable image quality. * Water Resistance: Features a multi-layer waterproof coating for easy cleaning and maintenance. * Light Control: Offers 1 to 9 stops of adjustable light reduction with 360-degree rotation for precise dimming settings, suitable for diverse scenarios. (Note: High settings may cause a temporary "black cross" effect, which is a natural phenomenon for adjustable ND filters with certain lenses and focal lengths.) * Design: Slim 7.4mm thickness with CNC-patterned design for enhanced friction, making attachment and detachment easy. * Glare Reduction: Oxidized sandblasting process prevents stray light and minimizes reflections on the metal surface. * Compatibility: Designed for all 49mm lenses. A 52mm lens cap is required for this filter.