Keep your muscles loose with a Hyperice Vyper foam roller and vibration massage ball. This two-in-one hypersphere weighs 2.95 pounds and has a diameter of 15.2 centimeters. This size helps users target muscles that need attention. The rigid structure of the hypersphere consists of a dense shell and silicone grip textured surface. There are three different vibration settings so that you can customize your pre- or post-workout session. It comes with rechargeable lithium ion batteries.