The Makita 18V LXT Lithium-Ion Cordless Heated Vest features three heat settings (high, medium, and low) for precise heating control with two core heat zones on the shoulders and back to provide optimum heat distribution. The vest's on/off heat controller uses three-stage LED indicators to show when the product is in use. The inside pocket on the rear left side holds a Makita 12V max pod-style battery (battery not included). The vest also uses an outside power source which accepts Makita 18V Li-ion batteries and compact Li-ion batteries; the power source also has a 2.1A USB power port for charging portable electronic devices (battery and charger are sold separately).