Tumble Drumm's Automatic Fish Scaler is portable, easy to operate, and cleans fish indoors or out with absolutely no mess. Plug the Automatic Fish Scaler into an outlet to clean up to 50 fish at once!How it WorksTo operate, pour approximately 3 gallons of water into the tank. Insert up to 50 fish of comparable size. Close the door and plug the unit into a 110-volt outlet, allowing the unit to run for about 10-20 minutes. After the fish are scaled, simply lift the drum out, open the door, and pour the fish out. Scales wash through the larger holes in the drum and settle to the bottom of the tank during operation, leaving the fish free of scales, dirt and slime.