About this item [Perfect Design] 5.5" in length and 2.5" in diameter, weight in 15oz. This siamese peanut-shaped massage ball is a perfect design to get to those hard-to-reach stabilizing muscles that surround your spine and vertebrae without applying pressure on them as you lay on it. This peanut massage ball is ideal for gifts. [Durable Material] The massage ball is made of high-quality silicone, which is firmer than tennis balls, but not like the hard plastic balls with knobs and they hurt. It is durable for long-lasting use. 3 colors have the same density for choice. [Special Shapes] The surface of our massage ball is designed with a unique striped shape, the main function is to prevent slippage and massage the muscles more deeply. Whether you're undergoing occupational physical therapy, workout fitness exercise everyday as an athlete, or just an average user who simply wants to get rid of fatigue after a long day, it's the perfect gift for you. [Workout Guide] The back massage balls are comfortable and easy to use according to the instructions. You can use it on painful localized parts of the body where trigger release is required while strengthening your core to stabilize. [Satisfaction] If, For Whatever Reason, You Don't Absolutely Love Your Massage Ball, Please Feel Free to Contact Us and We will be Here to Help You Any Time.