Reinsman West Coast Classic- 1/2" Copper hinge port. 8 1/2" cheeks, 5" mouth. 
 
"The hinge port continues to grow in popularity. Similar to a correction style bit, the hinge port moves in four places giving the rider the ability to independently move the shoulders, rib cage, and increase collection. The hinge port is a great choice for horses whom need to lift their shoulders and work on lateral movementys. Reinsman's Golden Glide bushings enhance the smoothness of theindependent movement on the West Coast Classic cheeks for more precise cues. Copper is a soft metal, check for signs of wear before use."