Model Number: DDSY283-KC Brand Name: Holleyintl Key Specifications/Special Features: ApplicationTheDDSY283-KC/DTSY541-KC is a keypad type prepaymentenergy meter. Users can purchase energy credit through vending network to get a serial number (named as "TOKEN"), and then use the keypad of meter to enter the TOKEN. The available credit will be added into the meter after the TOKEN being accepted. The TOKEN contains 20 encrypted digits. For the purchasing method reason, the meter also named as "Keypad meter". It complies with open standard STS.Features Payment feature realized by encrypted 20 digitstoken Alarm forlow credit/overload/fraud. Availability of RS485 and optical portfor meter readingand configurations. Terminal cover opening detection alarm.