The OM400 is a one-piece GPS/cellular electronic monitor ankle bracelet to track low to high-risk offenders 24/7, indoors and out. The OM400 allows you to signal offenders using vibrations and sounds and receive offender acknowledgment in return. Built on the rock-solid reliability of the popular OM210, the OM400 continues to provide reliable tracking services.

This device is also used for domestic violence monitoring programs. Devices are simultaneously tracked. If the victim and the offender come within a predetermined distance from each other our personnel can contact the victim and provide notice.

OM400 Features

  • Extensive store and forward capability in case of communication outage
  • AFLT technology tracks indoors and in GPS-impaired environments
  • Cut-free strap installation prevents false strap tampers
  • Acknowledgment button allow participants to acknowledge that instructions have been received
  • Advanced A-GPS technology quickens GPS locations
  • Touch enclosure for mechanical shock and impact resistance
  • Tamper alerts at strap, device, and backplate
  • Offender acknowledgment of beep + vibrate alerts
  • Available on both Sprint and Verizon platforms

For more information about any of our products or services, please contact Sentinel directly at or by calling (800) 589-6003.