The DSC WS4939 is a four button key fob that is designed for use with the DSC Impassa and various DSC PowerSeries Systems. The key fob features four distinct buttons for arming stay, arming away, disarming and triggering a panic. The device operates at a wireless frequency of 433 MHz.

This key fob offers some great functions and features. It is durable, scratch resistant and water resistant, allowing a user to carry around the sensor safely. Its included multifunction belt clip allows the device to be secured to a belt. It can also be attached to a key ring, or it can be down around the next as a lanyard. In order to reduce false alarms, the panic button on the key fob must be held down for at least three seconds before the command will go through. The device is powered using a CR2025 lithium battery.