Energizer alkaline battery, model 4LR44/A544, 6 Volt. 2 Batteries in blister pack. Equivalent models: 4NZ13, 4SR44, 544AE, A544, A544S, E544A, G13, GP544A, K544A, K544A, KS28, KX544, L544, LR544A, P544GA, PX28A, PX544A, R544A, RPX544, V28GA, V28PX, V28PXL, V544A, WE544A