RTR-500DC Handheld Data Collector for RTR500B Series Data Loggers. Allows immediate on the spot checking of collected data. Includes USB 2.0 connection to transfer collected data to a PC. RTR500DC can be used as a remote unit for up to 32 units per group, or as a repeater for up to 15 units per group and up to 7 groups. EU Frequency Range 869.7 to 870MHz @ 5mW RF Power. Range up to 150m line of sight. Unit can be powered via USB, 2 x AAA Alkaline Batteries, 2 x AAA NimH Batteries, or AC mains adaptor.