This multi-coated circular polarizer by SRP was specifically designed for use with SRP's BlurFix3 SO Naked and BlurFix3+ 55 filter adapters for the GoPro® Hero3 and Hero3+ cameras.  This filter features:

• Ultra thin frame design to eliminate mechanical vignetting
• Coatings applied to both sides of the filter to reduce reflections and lens flares
• Black rimmed glass
• Matte black super-fine frosted finish
• Knurled filter ring and polarizer adjustment ring
• Japan optics 

A circular polarizer reduces glare on the surface of water or glass.  It is a must have for fishing and watersport productions and in applications where a windshield is involved.  In addition, a circular polarizer will increase the contrast in your videos and photographs.  This filter is commonly used by areal sports enthusiasts to give clouds more definition and make the sky appear bluer.  Snow-sport enthusiasts will find that a CP filter will increase the contrast between snow and sky.   

Note: Camera and BlurFix3+ 55 filter adapter not included