The Port allows enough room for the horse's tongue to fit comfortably under the flattened area of the port. Relaxation and chewing are a common reaction to this bit which is perfect for horses that won't tolerate tongue pressure who often react with excessive head shaking. The Kimblewick is an effective combination of influence on the horse's lower jaw and pressure on the neck. The different rein attachment allows for a well-regulated bit. The cheeks offer a certain weight which quiets and relaxes nervous horses.