Stage C (neck reining - horse responds to poll pressure); Horses who respond well to poll pressure are in Stage C; Features include solid mouthpieces and cheek attachments, and swivel cheeks with jointed mouthpieces or low to medium ports; Responds faster by design with a mouth that increases control; Sweet iron is intended to rust and promotes salivation which makes a more supple feeling mouth; Mullen relief mouthpiece creates even pressure across the bars and tongue to eliminate the nutcracker effect