Reins are a key part of a rider's equipment. They provide a direct connection between the horse and allow for easy control and direction of the horse. Reins also help with balance and posture.  A rein is the strap attached to the bridle via the bit or a noseband, typically used to control and guide the animal. The first form of reins was a rope tied around the horse's mouth. This allowed the rider to pull on the rope to guide the horse. Today, however, there are many different types of reins to choose from. They can be made of leather, nylon or rubber and vary in length, width, thickness and style. Some are designed for specific horses while others are intended to fit any horse.