Polarizing Fluorescent Light Filter Sleeve Polarizing Light Filter Sleeves Filters out harsh glare with minimal change in light levels Polarizing light filter technology cuts glare from fluorescent lighting and allows up to 85% of original lighting to pass through. Lessens eyestrain, fatigue, and headaches. Reduces reflective glare on reading materials and worksurfaces by 50-80%. Easy to install; sleeves with protective end caps slip over existing fluorescent tubes in undershelf or overhead lighting fixtures. Manufacturers lifetime warranty for original purchaser. Universal Fit 4-ft. Length