... 2. 860-960MHz frequency adjustable 3. TCP/IP,RS232/RS485 Four-channel UHF RFID ZK-RFID401 is a high performance UHF ... , interactive and scanning work mode; l Low power dissipation with single +9 DC power supply;l Support RS232, RS485, TCPIP with ... 6001500mAFrequencyFREQ902 928MHz* Effective distance depends on protocol, tag and environment. Four Channel UHF RFID Reader