Anchor Liberty 3500 is a powerful sound system designed for both indoor and outdoor use. It features a two-way speaker system with a high-frequency tweeter and an 8" bass speaker, driven by a 75-watt MOSFET amplifier, delivering clear and powerful sound. The Liberty 3500 can be operated on either AC power or its internal rechargeable batteries, which provide 5-8 hours of operation per charge. It also has a built-in battery charger that automatically senses when the batteries are fully charged.