The Shock Doctor (R) Adult Ultra 2 STC ConvertibleMouth Guard features a sleek, low profile design so you can breathe deep and speak easy. Triple layer technology provides a tight, custom fit that disperses impact with strong, comfortable protection. It features a convertible tether for both strapped and strapless use. FEATURES: Advanced Gel-Fit liner custom-molds to teeth for a tight and comfortable fit Shock Transfer Core disperses impact to reduce injury Aero-Cushion Anti-Shock Pads for stronger, more comfortable jaw protection MORA Performance Enhancement positions lower jan down and forward for increased strength and athletic performance Convertible Tether detaches for both strapped and strapless use Model:7501A