I used it indoors about three times, but the sound was too loud, so I'm switching to a smaller speaker. Product Features: * Built-in lithium-ion rechargeable battery for outdoor use * Equipped with X-Balanced Speaker Unit, achieving clear high-quality sound, overwhelming sound pressure, and powerful sound (equipped with two 140x140mm large-diameter subwoofers) * Splash-proof (IPX4) * Guitar and microphone jacks * Bluetooth compatible Main Specifications: Battery Type: AC power, lithium-ion battery Battery Life: Approximately 20 hours (MEGABASS mode) Charging Time: Approximately 3 hours Size: Approximately W275mm x H572mm x D295mm Weight: Approximately 11.2kg (including rechargeable battery)