https://www.mccoys.com/shop/p/21220622/rayovac-a1604-2tk-9v-batteries-2-pack
2 Pack, 9V, Alkaline Batteries, Lasts As Long As Duracell Coppertop & Energizer Max, Ready Power Technology Increases Shelf-Life, Mercury Free Formula, Guaranteed Fresh For 5 Years.
Battery Size
9 V