DELL AD211, 5 W, 5 W, 100 - 20000 Hz, Wireless, Mini-USB, Grey DELL AD211. RMS rated power: 5 W, Speakers RMS power: 5 W, Frequency range: 100 - 20000 Hz. Connectivity technology: Wireless, USB connector type: Mini-USB. Product colour: Grey, Product design: Tube, Housing material: Plastic. Recommended usage: Universal. Battery type: Built-in, Power source type: Battery, Battery life (max): 10 h