This O-ring is made out of 5/16" diameter material. 2 7/8" outside diameter against the extra weight in the compactness of the ring allows for a more stable feel and quick release. The two-piece half and half mouthpiece combines a twisted wire bar piece and smooth mouth across the tongue. This mouthpiece is softer than a complete twisted wire.

Mouth: 5 ¼" Rings: 2 ½"