The Monster S310 Wireless Bluetooth speaker delivers wide dynamics with punchy bass, clarity and detail with no distortion at any level. You can easily connect two S310 speakers together to create left and right channels - combined output delivers powerful stereo sound, great for parties, movies, or music listening. With the included strap, carry the lightweight S310 bluetooth speaker anywhere. Plus a high-efficiency Li-ion battery lets you enjoy up to 24 hours of Pure Monster Sound from a single charge—longer than most ordinary outdoor Bluetooth speakers! A built-in microphone allows you to easily receive and make calls for a truly hands-free experience.