This Alpine 5 jet fogger/mister/water smoke maker uses ultrasonic sound to turn water into a mysterious fog, called a super power as it puts out five times more fog. There are no chemicals - safe for fish. Place the unit into the floating ring, then in about 1 to 2 inches of water, plug it in and you have fog/mist. The mist maker comes with a power adapter that provides 24 volts (low voltage), the floating ring and an outdoor transformer. Cord length from plug to transformer 3.7 feet and from transformer to fog unit 32.9 feet. Completely safe. For use outdoors. Fogs an area 6' 8" x 6" 8" with no wind. Floating ring center hole diameter 4 1/4", outer diameter 9 3/8". One-year limited guarantee also covers disks. Model FG201R; replacement disk size 20mm.