The Technical Pro MPHBattery is universal and compatible with most large megaphones including Pyle, Seismic, and Ampli-vox. The Technical Pro MPHBattery is simple and user friendly, with a built-in AC wall charger which opens and closes for convenience, and an LED indicator to let you know its fully charged. Any time you purchase a Technical Pro product you are protected by the technical pro guarantee. if at any time you are not satisfied, just reach out to us, and a member of our team would be happy to help you! Features: Designed to Work Technical Pro ER66 Megaphone Models Built in AC Wall charger LED charge status indicator Automatic charge protection Charge lasts for approximately 5-8 hours. Built-in rechargeable battery fully charges in approximately 4-6 hours For maximum battery life the battery should be fully charged prior to its initial use Dimensions (L x W x H):4.5"x 1.5" x 2.7"