DBEST PS4003 Duo Rechargeable Mini-Speaker Set - Rubberdized Black Engineered for exceptional clarity of sound Two powerful built-in amplifiers for a surprisingly loud volume High-capacity Lithium batteries for up to 48 hours continuous playback Internal magnets and ergonomic design to join the pieces Compatible with all audio equipment featuring a 3.5mm jack & all standard USB chargers (PC, Car, Mains)