Tech spec:
Input Voltage: 5V DC (USB PLUG)
Loudspeaker Output Power :3W * 2 RMS
Power supply : USB port
Frequency : 60Hz- 20kHz
Input Resistance : 4 Ohm
Works well with: Laptops / Notebooks/ Netbooks and when using external power source (e.g. power bank) they can be used with MP3 players / Mobile Phones / Smartphones, tablets, etc
Size of 1 speaker: 80 x 85 x 78mm