20 Volt MAX Compact Lithium Ion 4.0Ah Battery Pack (4 Pack) Number of Total Batteries Included:6 such as power outages ECONOMICAL such as power outages ECONOMICAL Cut heating bills by warming only occupied areas COMFORT Manually adjust the heat setting to your desired temperature SAFE Built in oxygen depletion sensor immediately shuts down the heater if carbon monoxide or lack of oxygen is detected CONVENIENT 1 continuous press of the battery assisted igniter makes ignition quick and effortless VERSATILE Includes all necessary hardware and bracket for wall mounting UPGRADEABLE Separately sold optional base legs (WBL100) provide the alternative of floor mounting ECO FRIENDLY: 1 The DCB240 2 20 Volt MAX 4 Ah compact lithium ion battery 2 Pack provides the highest capacity within the DEWALT 20 Volt MAX compact battery lineup Its small size and light weight provide ergonomic benefits for increased tool maneuverability and control for overhead applications