The Professional Choice 7 Shank Collection Wide Ported Chain Bit has more weight behind the mouthpiece. This allows quick release from the hands. If you are transitioning from an O-ring or D-ring bit, this one will be perfect for you! With the wide ported chain mouthpiece it is  a step up from the traditional ported chain bit. This bit is a little more aggressive on the tongue and pallet since it does not have much tongue relief. 

Professional Choice

7 Shank Collection

Wide Ported

Chain Bit 

5 1/8" Mouth 

6 1/2" Cheek