we need outdoor passive tag readers: RS-232, 10/100 Ethernet , I/O Digital / Frequency: 860 - 960 MHz / antenna power: 10mW - 1 W conduction ( 30 db ) / Distances: 8 meters read, 5 meters write / ISO 18000-6B, ISO 18000-6C , EPC UHF Gen 2, supports ISO 18000-6B y U code 1.19 / 4 antennas input, 1 data port / Operation ranges: -20? a 85?C, Humidity 5-95% / dust and water proof / minimum detection of 400 tags per second / antenna compatibility: Linear or polarized Minimum: 1000 fixed outdoor / 1000 mobile