The  Gas Boiler Power Supply Battery Case, Battery Box Plastic Universal Gas/Chimney Electric Boiler Battery Box is a set of three battery cases that are designed to hold D/LR20/AM1 batteries. They are made of durable plastic and are compatible with a wide range of gas boilers and other electrical appliances. Features of Flue Gas Water Heater Battery Box: Set of 3 battery cases Made of durable plastic Compatible with D/LR20/AM1 batteries Universal design Easy to install Specification of Flue Gas Water Heater Battery Box: Material: Plastic Color: White Dimensions: 130x70x30mm Weight: 100g each Battery type: D/LR20/AM1 Dimensions: Length: 130mm Width: 70mm Height: 30mm Uses: Gas boilers Other electrical appliances that require D/LR20/AM1 batteries Package includes: Flue Gas Water Heater Battery Box