Our 3-rings side piece, named Pegase, is made from food stainless steel. It is a noble material with excellent properties:
sustainable
corrosion resistant
biocompatible: no release of chromium (toxic) in contact with saliva
The amount of pressure and leverage effect is controlled by the rider. The level of control depends of the use of the 3 rings. The lower the ring the more leverage and control the rider will have.
The side pieces are here sold without the mouthpiece.