The BlurFix3™ SO Naked slips over the GoPro® Hero3 housing and allows you to mount 55 mm filters to your camera.  This adapter is precision CNC machined out of Delrin® which is more expensive than billet aluminum but flexible enough to allow for a clip-on fit.  This is the same frame that is sold with the "BlurFix3 SO Featuring the CYD Dome filter by URPRO" only without a dome filter.

Testing Notes:

No vignetting observed in any mode below water using the ultra-low profile URPRO color-correction filters (CY, GR, and SWCY) available from SRP. There is vignetting in 960p WIDE video mode and photo mode above water with these filters, although they are intended for below water use only. The magnification factor under water removes the vignetting underwater in all modes. 

For above water use, the ultra-low profile Marumi CPL, ND4, and ND8 filters offered by SRP may have mechanical vignetting in 960p and 1440p WIDE video mode and photo mode -- this is camera dependent. Depending on the camera there is little or no vignetting in the WIDE WVGA, 720p, and 1080p modes. Off-the-shelf 55 mm filters have not been tested by SRP, however, due to their high profile we anticipate that these filters vignette in all modes. We have tested the BlurFix3 SO on a variety of GoPro(R) Hero3 White, Silver, and Black cameras. 

Note: Camera and filters sold separtately.  Not compatible with the new Hero3+ standard housing.