Type DDSY999 single phase static prepayment energy meter are new age intelligent meters combinating advanced integrated-solid technology and STM crafte. The performance accords with class 1. 0 single phase  static energy meter of IEC1036 and GB/5460-91 standards, as well as prepayment meter of GB/8382-96 standards. They feature advanced and sensitivity, long service life, strong overload and anti-power threft, alarming of remaider, storing data over ten years, setting secrect, etc.