The AA Button Battery Pack is a great portable battery pack when you want to be able to press the button through clothing or other items. The large haptic button on the front makes it accessible to press and feel. Powers up to 12ft of EL Wire, 30ft of EL Tape or VynEL™ or up to 48ft of SewGlo™ thread. Two blink modes as well as a constant on function are accessible by toggling through the power button. LED Indicator light when power is on.