SVP model SA400 siren box, standard features are wail, yelp, and phaser, also has airhorn and manual features, can be wired for horn ring function and also does radio rebroadcast. 100 or 200 watt. These sirens have some of the most pure sound and great quality of any out there. Listing is only for the SVP SA400, the siren seen in the middle of the others in the photo.