Trust Sweet Iron Medium Port Swales BitThis is a straight mouthpiece with a medium port. The port allows freedom of the tongue. The port creates space for the tongue and decreases the pressure on the center of the horses tongue. More tongue freedom is ideal for horses that have a sensitive tongue or horses that stick out the tongue. The Sweet Iron bits are made of steel and have a recognizable blue color. Sweet Iron will rust when it comes into contact with (air) humidity, the surface rust