The PRO-3540 includes a radar antenna and a Laser Lens module which can be installed remotely inside the vehicle; this allows users to conceal the radar devices from view. Both the antenna and lens connect to a receiver unit that displays information on a blue LED display. The PRO-3540 control panel can be mounted three different ways as the user sees fit, and the text information display can be changed accordingly.
The Whistler PRO-3540 includes different audio alert features such as a distinct alert for each detected radar band, a unique stay alert mode that chimes every 30 to 60 seconds, 3 city modes and a highway mode, and quiet and auto quiet modes for times when the user requires the device to be silent. The device city modes are designed to help eliminate false radar detections in a highly populated area; some false detections can usually be made from automatic door openers installed in nearby stores which use the X band radar emission and the city modes turn this detection band off.
Whistler claims that all PRO radar devices have a unique POP detection mode; modern radar guns can be set into a special POP mode allowing the device to be used without detection however all of Whistler's PRO model detectors including this one will still alert the user to said detection mode.