The engineering design of the monitoring device thwarts most potential attempts by the offender to circumvent the system; the device contains a backup electrical system, reports power outages and any interruption of telephone service, cannot be stretched enough to allow removal, and contracts when subjected to a heat source. A computer traces the activity of the defendant; the accuracy of the machine appears to be excellent. This article discusses the sentencing and probation procedures to be followed when using electronic monitoring, the finances of the program, and the psychological effectiveness of the device.