Elmo-Tech's Group TRaCEr portable monitoring unit is capable of monitoring groups of offenders within a 300-foot radius through four definable range settings. Upon demand, the monitoring range can be widened, effectively doubling it. The unit receives signals from the tags worn by the offenders. Any attempts to tamper, remove the tag or get away from the designated monitoring range will trigger an audible alarm on the monitoring unit itself. The name of the offender who has tampered with the tag or gone out of range simultaneously appears on the unit's LCD screen with the nature of the event.