It combines two actions, but doesn't replace the finesse of a true double mouthpiece.

To educated horses, stable in contact and ready to work in a more collected frame.

Refine the balance, the position of the neck, and the collection through moderate leverage.

No. It's part of a double bridle and must be used with a snaffle bit.

Some are, others are specific to a type of bridle or noseband. It is important to check compatibility.

It depends on the horse. Many riders alternate between the snaffle and the double bridle.

Yes, if it's anatomical and well-fitting.

Yes. The rider must perfectly master their hands and the use of both pairs of reins.

It is widely used in dressage, but can be employed in any discipline requiring finesse and precision.