Myler SS 7 Flat Shank Correctional Port Barrel Stainless Steel 7" Flat Shank with Sweet Iron Correctional Ported Barrel (MB 41PB, Level 2-3) Copper Inlay Mouth 5". This mouthpiece is made of polished Sweet Iron which naturally oxidizes or rusts. Harmless to horses, it has a sweet taste and promotes salivation. Features: Correctional Ported Barrel Copper Inlay Mouth 5" Naturally oxidizes Promotes salivation Item Specifications: Size: 5