Duracell Duracell Coppertop 9V Battery, 2 Pack, Long-lasting Power, All-Purpose Alkaline Battery for your Devices 004133303961 - The Home Depot
Alkaline 9V Battery : ID 1321 : $1.50 : Adafruit Industries, Unique & fun DIY electronics and kits
Amazon.com: Duracell - CopperTop 9V Alkaline Batteries - long lasting, all-purpose 9 Volt battery for household and business - 2 count : Health & Household