This Sports Radar 65 MPH X Band (model: TUNING-FORK) Tuning Fork Radar Gun Accessory is a used to verify the accuracy of a Sports Radar radar gun. This Sports Radar Tuning Fork is used to calibrate the radar gun as well as the remote display. Both units normally come calibrated and rarely need recalibration. However, if or when they do, this tuning fork provides a quick, simple and inexpensive way to calibrate your sports radar equipment with no hassles and no waiting. Instructions for using the Sports Radar Tuning Fork do, of course, come with the tuning fork itself.