Reinsman Premier 3/8" copper bar ball port correction bit. 6 1/2" cheek with 5" mouth. 
 
"Premier series performance bits are Reinsman's very best. They feature a heavy stock and a no-pinch ball hinge connection. The ball port correction is designed with a 3/8" copper bar to ensure a supple mouth and mild palate pressure to aid in response to subtle cues."