Vktech 1.55V and 3V Button Cell Battery Checker Battery Tester Green Suitable for: 1.55V and 3V Button Cell Battery Size: 9.9 X5.4 x2.8cm When the pointer point at red district, indicate the battery is in a low power condition, you need to replace Color: Green When the pointer point at green district, indicate the battery is in a good condition, you needn't change