High-performance audio system with dual speakers and passive radiators delivers loud, clear sound with deep, accurate bass. Durable, portable, stackable design features shock-absorbing end caps and metal speaker grills that protect from drops and other risky conditions. Best-in-class reception, accuracy and signal quality. Integrated handles allow for easy transport and storage. Digital AM/FM tuner with 10 station presets. Customizable EQ (equalizer). Weather-sealed auxiliary compartment for outdoor use. 2.1 amp USB charger for all portable electronic devices. 3.5 mm aux in port for wired playback (cable included). Powered by all M18 batteries or A/C outlet (battery not included); up to 12 hours run time with an M18 5.0Ah battery.