Unlike other mouth guards (with a heavy spring) that tend to excessively extend the temporomandibular joint, the mouth guard designed by iM3 features a unique locking system that requires little force to maintain the desired opening inside the animal's mouth. The lightweight and spring-loaded guard, along with the unique locking system, reduces the risk of myalgia, neuralgia, and/or trauma to the temporomandibular joint. It has an opening width of 5 cm.