The three piece smooth gives you similar benefits of the smooth snaffle with added flex and bend. Brittany Pozzi
 
The combination is a great transition from the o-ring. The combo uses the rope nose and gag to simultaneously ask the horse to break at the pole and give you more leverage. I like this bit for training, tuning, and competing. Mouth: 5 1/2" Rings: 3" Brittany Pozzi
 
NOTE: This bit will rust when exposed to moisture. This creates a sweet taste in the horses mouth and promotes salivation.