A3385-SPK0021 is a wired one-channel 100 watt electronic siren bundle that can play custom-made MP3 format recordings, it matches with a 100 watt octangular speaker. The attached remote control is with built-in memory card so that you can connect it to your PC or laptop to upload your own custom-made MP3 format recordings to play. Equiped with two auxiliary light terminals on the main siren box makes it possible to run two-channel 12V Led Lights and is with easy light control on the backlight designed remote. It has PA system to broadcast, you can press and hold the button on the side of the remote and speak towards the microphone sound pickup hole. And it contains more than 20 different tones by default to fit for different vehicles like Police, Ambulance, Fire, Breacher, Engineer and some other Special Operation Vehicles. With simple installation, convenient operation and stable performance, this siren would be a good choice for those vehicles and ocassions that have the demands for PA system and/or audio warning.