Feature:1. 1. The massage ball can massage the shoulders, back, waist, legs, arms to relax the muscles.2. 2. Hot and cold two-in-one design; as a cold massage ball, you can put it in the freezer for two hours until it cools; as a hot massage ball, you can put it in a bowl of hot tap water 5- 10 minutes.3. 3. This cold manual massage ball is inserted into high-quality stainless steel and injected with cold glue, which can perform more cold treatments. No matter how long it is frozen, the massage ball will not break as easily as another ice pack.4. 4. Help reduce fatigue, pain, cramps, stiffness, and effectively reduce inflammation and swelling.5. 5. The roller of the fitness massage ball can rotate 360 degrees, so you can easily place it on the injured part and roll it in any direction. The metal massage ball is also movable, which is very suitable for shin splints, plantar fasciitis, back, neck and shoulder pain!6. Specification:Material: stainless steel+PPProduct size: base diameter 6.5cm, height 6.1cm, ball diameter 5.4cmSingle set weight: 150gApplicable scene: fitness body, health massagePackage List:1*Cold Massage Roller BallHow to use] The sphere can be used for more than 6 hours after being iced for 2 hours. The product sphere is always very low temperature, cold and iced. It has a good physiotherapy effect for athletes or fitness enthusiasts. It can also be used for hot compress massage. It can be used after 15-20 minutes of soaking in hot water. It can be used for muscle strains and hamstrings, poor blood vessels.