Yamaha PDX-31, 2.0 channels, 30 W, 3.15" (8 cm), iPhone, iPod, Red, Digital Yamaha PDX-31. Audio output channels: 2.0 channels, RMS rated power: 30 W, Driver diameter: 3.15" (8 cm). Apple docking compatibility: iPhone, iPod. Product color: Red, Volume control: Digital. Weight: 3.75 lbs (1.7 kg). Dimensions (WxDxH): 13.8 x 4.92 x 4.29" (350 x 125 x 109 mm) https://www.gadgetreview.com/yamaha-pdx-31-portable-dock-review ProsLittle to no sound distortion or interference One-size-fits-all for current iPods and iPhones; plus an AUX-in Crisp, clear audio presence at medium volumes ConsIsn’t actually “portable” with a 15-volt requirement Bass is present, but not impressive... Little to no sound distortion or interference, Onesizefitsall for current iPods and iPhones; plus an AUXin, Crisp, clear audio presence at medium volumes, Isn’t actually “portable” with a 15volt requirement, Bass is present, but not impressive, For $40 more, doesn’t improve much on PDX30