Energizer MAX Alkaline Power Seal AA Batteries are designed for long shelf-life of upto 10 years with stainless steel pre-coating that prevents leakage and advanced ingredient formulation that helps them maintain their power over time. This contains no mercury or cadmium which makes it safe for the home and better for the environment. Ditch the primitive battery and switch on to this advanced technology battery which are safe and reliable. This value pack comes with 2 extra AA batteries in addition to the pack of 4.