Korsteel® Curb ChainKorsteel Curb Chain prevents the curb bit from rotating too far in the horse's mouth. When the reins are applied, the curb chain engages and puts pressure on the chin. The chain must sit flat to avoid uneven pressure and be fitted correctly to prevent the bit from rotating more than 45 degrees in the mouth. Each. Hooks are sold separately. Imported. Stainless steel. 9. 5" long end to end.