Reinsman Western D-ring snaffle. 3" rings, 5" mouth with sweet iron 7/16" twisted wire.
 
"The Dee ring applies pressure to the horse's cheek on the opposite side of the face from the rein you pull to allow better flexion.Excellent bit for young colts or older horses that need a little more control. Sweet iron is intended to rust and promotes salivation which makes a more supple feeling mouth."