Model 66CGB3S. 6.6x6.6" (6x6") size for use with matte box. Retails originally for $474/each.
The Tiffen 6.6 x 6.6" Blue 3 Soft Edge Graduated Filter is a soft-edged graduated color filter providing a bluish color across the image, giving a cooling effect for your photographs. The graduated filter design keeps a portion of the image neutral, resulting in a more realistic look while allowing for the sky or other bright areas to take on the color of the density.
The 3 density provides less of a blue cast than the 4 density filter, but more than the 2 density.
This filter is made using ColorCore technology, a process that involves laminating the filter substrate between two pieces of optical glass, and grinding flat to a tolerance of 1/10,000th of an inch. This filter measures 6.6 x 6.6" / 167.6 x 167.6mm.