Silver card selection 4 7th, the battery zinc absorption and chemical production. Silver Card 4 Festival 7th battery using Silver Blister card packaging, mainly used in clocks, toys, items such as anti-theft devices, low power consumption, long service life. Silver Blister card 4, 7th the battery per card 4, each piece of 1440, quantities of it. Silver Blister card 4 7th, the battery is 0.33 Yuan each.