Genuine 67mm UR/Pro underwater color correction filter -$65 ono plus shipping.
A brand new copy of this filter will set you back $130, so why not grab one for half price?
This filter is very handy for shallow water shooting without flash. See the Wetpixel review: http://wetpixel.com/...-filter-review/
The filter ring has marks as shown in the pictures, but otherwise is in good condition with clean glass. The filter comes with the original UR Pro case.
