Manufactured by Alexander. I call this product a necessary 'torture device' for learning how to play in the upper register without excessive pressure. When the player pushes too hard the device releases the air out of a side chamber. You can adjust the spring inside so that it will release the air at different pressure levels. Be forwarned: If you set this device at a low setting - you will be tempted to throw your horn in frustration!
Cost: $109.95
