Tri-fold construction allows for quick folding and unfolding so it is compact enough to fit in your pocket for portability. The attachment allows it to be securely attached to most smartphones without additional tools, making it easy to set up and remove without damaging your device Includes 15mm expandable bracket for flexible positioning to accommodate a variety of phone models and lens placement. This solves the problem of misfocus and ensures accurate adaptation and better results The rounded clip securely attaches to your phone's lens module, eliminating stray light, glare and fogging. Combined with high resolution optical glass for crisp, detailed images without distortion Equipped with CPL filter to reduce reflections from non-metallic surfaces such as glass or water Increases saturation and contrast of landscapes and still life photographs You can stack them with CPL, star using a single mount for versatile and creative photography in a variety of scenarios. This expandable design allows for a variety of optical effects