The Shires Two Ring Sweet Iron Gag Bit With Raised Ribs is designed so that moving the rein between the main ring and bottom ring allows more control. The sweet iron and copper encourages the horse to be softer in the mouth. The 5" and smaller sizes of this bit come with shorter cheeks to ensure the bit remains in proportion with the smaller head. In addition, the raised copper ribs encourage salivation making this bit ideal for dry mouthed horses and also helps to encourage lightness for horses that lean on the bit.