Trust 2.1 MP3 Speaker Set SP-3550B UK, 2.1 channels, 15 W, 145 x 150 x 165 mm, Wired Trust 2.1 MP3 Speaker Set SP-3550B UK. Audio output channels: 2.1 channels, RMS rated power: 15 W. Subwoofer dimensions (WxHxD): 145 x 150 x 165 mm. Connectivity technology: Wired