This Focus Board has two sides, one is 18% gray, the other side is white. All gray, target "+" mark and white surfaces of this focus board have their own function. Whatever you used in film or digital photography, the 18% gray side can control expose value, the white side can balance the color and the target "+" mark can provide accurate center photometric. This focus board helps to revert the color truly and perfectly by measuring the exposure value, white/gray balance value and color temperature. Provides a great advantage when working under pressure in events such as weddings or parades. It is the ideal accessory of the portrait, flower and conversion shoots Specification : Material: PU, could be cleaning with water, with a nylon carry case Size: 30 x 30cm/12 x 12" Quantity: 1 PC Package includes: 1 x Focus Board with Gray/White Side 1 x Carrying bag