PP3 / 9V rectangular batteries including Alkaline, Rechargeable NiMH, Zinc Chloride and Lithium chemistires. For use in smoke alarms, childrens toys, radio microphones and many other devices. They are rectangular prism shape with rounded edges and a polarized snap connector at the top, we get a lot of customers refer to them as the "square shaped jobbys"! Most PP3 alkaline batteries are constructed of six individual 1.5V LR61 cells enclosed in a wrapper. Lithium 10 year life PP3's are best for use in smoke alarms and devices that need a reliable, long lasting battery. For the frequent user, NiMH rechargeable PP3's are best as they are most cost effective. Alkaline and Zinc Chloride PP3's are ideal for sporadic use.Fire Alarm Batteries. Duracell PP3 Batteries. Duracell 9v Batteries. Panasonic PP3 Batteries. Panasonic 9v Batteries. GP PP3 Batteries. GP 9v Batteries. Ansmann PP3 Batteries. Ansmann 9v Batteries.