Bluetooth 5.1 connectivity enables easy wireless connection to Bluetooth-enabled devices like smartphones and tablets Also includes a 3.5mm port and USB port for wired connections to audio devices and accessories Compact size and detachable carry strap make it easy to bring with you anywhere Built-in battery offers up to 20 hours of battery life on one charge Optimized audio design features two 3" 15W woofers, two 10W tweeters, and two passive radiators for louder sound Multi-speaker Stack session lets you pair with other Middleton speakers for a surround-sound experience Tough IP67-rated construction protects from dust and splashes, enabling outdoor use PVC-free speaker uses 55% post-consumer recycled plastic for a more sustainable build