Fulfillment by Amazon (FBA) is a service we offer sellers that lets them store their products in Amazon's fulfillment centers, and we directly pack, ship, and provide customer service for these products. Something we hope you'll especially enjoy: FBA items qualify for FREE Shipping and Amazon Prime.If you're a seller, Fulfillment by Amazon can help you grow your business. Learn more about the program. YMX BOXING Reflex Ball - The headband is made of high-quality materials. It is not only elastic but can also be adjusted with Velcro so that it fits more head shapes and is more comfortable to wear on the head. Each set contains two headbands and two primary balls. Now you can invite your family and friends to train together, PK! :) PRIMARY BALL has the same weight as the red ball and is a little softer than the red ball, but with different elastic cords. The ball will bounce back a bit slower than the red ball. Suitable for beginners. ADVANCEO BALL weighs about 25 grams and is equipped with a white elastic cord. The rebound speed is a bit faster than the PRIMARY BALL. Suitable for training in the second stage of training. The PROFESSIONAL BALL weighs about 35 grams, which is about the same as the rebound speed of the red ball. As the ball is heavier, it must be used in the third stage of training. Don't worry, each YMX BOXING ball has holes in the center and can easily complete the replacement of the spare rope without the need for any tools. Each ball is equipped with a dedicated spare rope to replace, doubling the life of the appliance.