CoolBox Cool Stone 10. Driver diameter: 5.3 cm. RMS rated power: 10 W, Impedance: 4 Ω, Signal-to-Noise Ratio (SNR): 65 dB. Connectivity technology: Wired & Wireless, Bluetooth range: 10 m, USB connector type: Micro-USB B, USB Type-A. Product type: Stereo portable speaker, Product colour: Black. Recommended usage: Mobile phone / Smartphone, Compatible memory cards: MicroSD (TransFlash)