Mennon multifunctional gray cards are made of organic material including independent gray card white card black card semipermeable card. Multifunction gray cards are compact portable waterproof not easy to scratch and breakage. It's suitable for photographers to use in harsh environments in outdoor. The gray card and white card is to measure the color temperature by reflective way to reach the color balance. Semipermeable card is to measure the color temperature by a transmissive mode to reach a balance of color. Black card is to reduce the high light part exposure reduce and balance the contrast scenes by appropriate shelter of the high light part when shooting high contrast scenes.