Material: [base material]: polypropylene, [ball material]: synthetic resin, [product size]: base diameter 6.5cm, height 6.1cm, ball diameter 5.4cmThe resin massage ball is composed of a base and a ball. Holding the base, the ball can roll 360 degrees. It is a great tool for modern people or athletes who sit for a long time with a hunchback, play 3C with their heads down, and have reduced thoracic spine mobility It is mainly used to massage the neck, thoracic spine and erector spinae (muscles on both sides of the spine). It can also be used to roll plantar fascia, calf, thigh, neck, etc. Press where its uncomfortable There is a round hole at the bottom of the base, which can be used to drip essential oils together to promote the absorption of essential oils, killing two birds with one stone Resin ball design, 360-degree rotating massageMultifunctional, suitable for various parts of thighs, calves, chest, arms and neck