It's clean because I haven't used it much since I bought it. Recommended sports: Running, marathon, all ball games (baseball, soccer, basketball, volleyball, handball, tennis, badminton, table tennis, rugby, American football, lacrosse, hockey, etc.), track and field, swimming, skiing, snowboarding, skating, gymnastics, rhythmic gymnastics, and all other sports. Use at home: To wake up your body in the morning, when you feel tired at your company desk, for massage at home, for massage after returning home. For myofascial release (warm-up, cool-down, massage).