Many newer aftermarket alarm systems are two-way systems. This enables a user to get feedback from his or her vehicle about the status of the alarm system. The vast majority of these systems use a remote control that has an LCD or OLED screen so information can be displayed about which sensor is setting off the alarm and other information of that level of detail. However, a few aftermarket alarm systems use an LED display on the two-way remote transceiver. In this case, less information is available about what is happening at the vehicle.
The main user of LED displays on two-way remote transceivers is Directed Electronics. It has two-way systems with LED transceivers marketed under brands such as Clifford, Python and so forth.