High-hardness scratch-resistant glass material: The lens is made of high-aluminum glass with higher hardness, resistant to scratches from sand and dust during flight. The high-quality white glass base offers excellent light transmittance, ensuring color accuracy during high-speed dives. Metal frame: Constructed from CNC aluminum material, the frame is strong, lightweight, and resistant to deformation. It provides effective impact protection and helps prevent the filter from loosening, shifting, or falling off. ND filter: Reduces incoming light, prevents image overexposure, and maintains natural motion blur during high-speed flight. UV filter: Clear and colorless, it physically protects the lens from scratches caused by branches or gravel while preserving original image quality. Multiple specifications: The set includes UV, ND8, ND16, and ND32 lenses to suit a variety of everyday shooting conditions. Name: Filter Kit. Compatible with: O4 Air Unit Pro. Filter types: UV, ND8, ND16, ND32. Product appearance and printed markings may vary slightly by batch, but this does not affect functionality. Color: As shown. Material: CNC aluminum + high-aluminum white glass. Package Contents: 1 x Filter Kit (filters only; other items not included). Note: Lighting and display differences may cause slight variations in color between the image and the actual item. Measurement tolerance: +/- 1-3 cm.