Sunset Ruby Style Chin Strap, CS007M, Size: Medium. This model is Non-Adjustable. Durable Material: Made from one piece of soft latex-free neoprene and stretches to fit perfectly without the use of hook and Loop straps Perfect Fit: Medium (22-23 Inch) chin strap for comfortable wear Cups the chin at a lower angle to provide maximum support and stay secure all night Vibrant Color: Eye-catching Ruby Red Latex-free. Hand wash only. Lay flat to dry. Measuring for Fit: Measure from under the chin, up around the top of the head, and back down to the chin. Once measured, check the size chart to for the proper size needed. Ruby Chinstrap Medium