Model number: ECG-903 ( Three channel) Dimension:300mmX230mmX61mm Packing:375mmX295mmX195mm Weight:4.5kg(gross); 3.57kg(net) Built in RS232 interface (USB is optional) Model number: ECG-903 ( Three channel) Dimension:300mmX230mmX61mm Packing:375mmX295mmX195mm Weight:4.5kg(gross); 3.57kg(net) We could supply ECG machines with 3 channels,6 channels,12 channels. If you have interest you could visit our website for the detailed information.