The WHOASIS horse trailer watering system allows you to furnish drinking water to your horse during trailer travel. The horse trailer watering system includes a 25-gallon water tank, a charcoal-activated filter, three troughs, a submersible pump, fittings, and tubing. The watering system fits into horse trailers with or without hay mangers. Wire it directly into your trailer, or attach it to a 12-volt battery. You can easily disconnect the watering system at the pump to fill a bucket or rinse off your horse. Cost: $499. Contact: WHOASIS, (719) 347-3056.