Horses always wear a bridle and a bit so that the jockey can control them, but there are a a variety of other tools a trainer may utilize to help the horse. A shadow roll is a piece of fleece that is placed over the nose band of the bridle. This prevents horses from seeing shadows and trying to jump over them. Blinkers are another tool that may be used, Blinkers are rounded pieces of plastic that are attached to a hood to prevent horses from seeing what's happening next to or behind them, keeping them focused on going forward. To help with the horse's breathing a trainer may use a tongue tie. This holds the horse's tongue down to its jaw to prevent blocking of the airway.