Duracell Procell industrial 9 Volt Battery are constructed using Super Conductive Graphite technology in the cathode that produces long-lasting power and outstanding performance. Each battery is tested for voltage and leakage before release to ensure dependable power, even after up to seven years of storage. Designed to operate in temperature extremes from -4°F to 130°F and provide unparalleled performance in audio electronics devices. Simply the best quality alkaline battery available. Great for use with active electronics and effects pedals. Used and trusted by countless guitar techs around the world an in our workshop!