The Edge series from Vulkan is made from a strong but lightweight polyester/spandex blend. There's just enough spandex in the material to prevent the shorts from restricting movement or tearing. The internal drawstring is easily adjusted, and the waist is closed via two-way hook-and-loop straps. Whether you need to store your mouthguard between sessions or store your mp3 player during circuit training, Vulkan has included a hidden side pocket. The pocket features a tight hook-and-loop closure to prevent snagging during grappling drills/training.