The Premium Digital Grey Kard model DGK-2 is a calibrated and tested white balance card / digital color correction tool for digital photography. The DGK-2 consists of three calibrated color reference cards, both sides matte finish and spectrally neutral. Each card measures 2" x 3 1/4" or approximately 50 by 83 millimeters. The cards are supplied with easy to follow instructions and a premium adjustable carrying strap with detachable clip and safety release.