Feature: They have different levels, you can pick the proper ball to use, and you can also share with your family members and friends, invite them to use the balls with youRaised design: the raised design on the reaction balls will not only make you feel uncomfortable, but also help you massage the parts of your body, they can be widely applied to help you relax your muscles and relieve fatigue after you exerciseServiceable material: the massage ball sports equipment is made of high quality material, this material is durable, so the balls can you a long time, you will not have to worry they will easily break or deform, and they will not hurt your skin or hands when you use themPortable size: the size is suitable to carry and store, you can take the balls in your pocket and carry-on bag when you go out, you can also put them in drawers or cabinets when you need not to use themAvailable occasions: the reflex reaction balls are widely applied , in gymnasiums, and on training grounds, they can be served for both bodybuilders and athletes; According to the simple appearances, men, women, adults and adolescents can use them without stresscolour:Pink+blue+green+yellow+redMaterial:rubbersize: 5.5 x 5.5 x 5.5CMPackage Contents:5 x reaction training ballsOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.