Chest to Bar Pull ups
Just like it sounds! Instead of the normal standard of just the chin over the bar, you must make physical contact of the bar with your chest. The standard is to touch between your nipples and clavicle. The only real difference is that some people have a slightly wider grip to allow the chest to fit between the hands. This is a great movement to practice towards getting a muscle up and learning how to pull through a greater range of motion.