Opteka Pocket-Sized Grey Card White Balance Card 18% Exposure Photography Custom Calibration Camera Checker Set with Quick Release Lanyard for Video, DSLR and Film Neutral 18% Grey / Gray Card with matte finish for scratch resistant. Non Reflective and Waterproof. Perfect for setting exact color balance. Works with any digital camera. Perfect for DSLR, Video, Film and Photography. Card size:3 1/3 x 2 1/8 inches. Small enough to keep in your pocket or on a key-chain. Compact, sturdy and Lightweight. Net weight: .32 oz. Package includes three color calibrated reference cards and premium landyard with a detachable clip.