A micro-electromechanical system switch formed on a substrate, the switch comprising a transmission line formed on the substrate, a substrate electrostatic plate formed on the substrate, and an actuating portion. Each hinge bonds to the main lens and one of the at least one peripheral lens to connect the main lens and the peripheral lens and provides a resilient cushion between the main lens and the peripheral lens to keep the lenses from breaking. The stop system limits the relative angular displacement of the mouthpiece members from a reference position towards the rear of a horse.