STS Prepaid Water Meter LAISON STS Prepayment Water Meter System consists of smart water meter and separate keypad, which is defined as Customer Interface Unit (CIU). STS Prepayment Water Meter System consists of smart water meter and separate keypad, which is defined as Customer Interface Unit (CIU). By adopting Radio Frequency Communication Technology, Smart Water Meter could communicate with CIU conveniently to realize remote meter recharge, parameter inquiry etc. functions; which provides comprehensive, reliable, advanced smart prepayment solutions to water utilities & authorities. Moreover, Automatic Meter Reading with/without valve control (AMR/AMI) function is also available, which could realize remote meter data collection & monitor; It is compatible with both velocity and volumetric type water meter, which comply with OIMLR49, ISO4064. and conforms to STS standard protocol.