A series of high precision DC Voltage Standard, AC DC voltage divider, Coaxial Shunt, WideBand Buffer, Current Transfer Standard, Current Transformer, Current Shunt, Current Transducer, Resistance Standard with high stability, high accuracy, low temperature drift, small volume and easy to carry, among which optimum and best uncertainty can reach 0.2ppm@DC, and can sastify with diversified reference standard application scenarios.