A Steam Whistle/Steam Horn, with hissing steam sound. The tone is adjustable from whistle to horn. For 6 - 12volts; three I/C design has adjustable whistle tone and volume control; 1 Watt maximum output. 2 inch to 3 inch mylar speakers are recommended for steam whistle, and 4 inch mylar speaker for steam horn. Case size 55mm x 40mm x 20mm.