The softest of the two O Ring styles, Smooth Snaffle mouthpiece is 3/8" in diameter, 5" wide, and curved to shape the mouth. Inlaid copper promotes salivation and greater sensitivity to the bars and corners of the mouth. Great for starting colts, training, or pleasure riding. A step up from the Smooth Snaffle, the Twisted Snaffle features a 3/8" x 5" stainless steel twisted wire mouthpiece. Each side is twisted in opposite directions, so when pressure is applied to either side, the horse realizes the same sensation. It creates greater sensitivity to the mouth. This is a great bit for training and softening the corners and bars of older horses to become more responsive.