DGK Color Tools Optek Premium Reference White Balance Card Set- 3 Card Set- 3 Card Digital Color Correction Tool -- Includes three color calibrated reference cards, carry strap, user guide -- Each card 3.2" X 2.2" 0.1" (8.3 by 5.0 cm) waterproof plastic -- Works with any camera JPEG, RAW, film or digital -- Dependable performance and accuracy. -- You must buy from DGK Color Tools to get guaranteed genuine DGK Color Tools Product