Vu Sion 37mm Slim Circular Polarizing Filter (VSCPOL37) 5 Year Limited Warranty: Covers defects of any kind in the workmanship and materials of the product. Unsurpassed Optic Resolution: Our filters are held to the highest optic resolution standards and will not degrade your image when placed in front of a lens. Flat Wave Overcoat: Optic coating that gives the filter's front surface a "smoother-than-glass" finish, making filter maintenance and care much easier. White Balanced Multi-Coating - Specially formulated coating process that ensures that there is no color shift when placing the filter in front of a lens. Hand Crafted and Inspected - Run in small batches, hand crafted, and individually inspected to ensure the utmost in quality.