The Happy Tongue is a solid mouth piece. It is curved and ported to give tongue relief. The Happy Tongue would be a good place to start if your horse is:
The rider will know immediately if this is the correct bit, as a horse with a sensitive tongue will finally begin to work into, and accept the contact. Changing the cheekpieces would then allow the rider to adjust the level of control.
The Loose Ring allows for immediate release and relief from tongue and bar pressure. The bit is immediately reset to a neutral position in the horse's mouth.