POP Mode, when turned on, enables the detection of a special band of radar known as “POP.” This is a very short transmission signal that allows the user of a radar gun to capture a quick read of a vehicle’s speed prior to setting the gun to another band. K40 recommends that you keep the POP Radar Mode turned off for two reasons: 1) POP radar does not transmit long enough to gather information needed to issue a speeding ticket, and 2) keeping POP Mode “on” is known to cause far more false alerts than actual alerts.