77mm Bullet Optics Protective All Purpose HD (HIGH Definition) U.V. Filter for Canon EF 20-35mm f/3.5-4.5 USM Lens

This Bullet Optics UV Filter prevents the Ultra Violet light from the sun to get into your picture which can cause blur and blue casting. This protective filter screws on top of your lens and protects it from any scratches or drops. UV Filters are ideal for photography the pictures gain clarity clearness and blue casts are eliminated.