Core Prodigy Fit Grips Sport - Round Sphere Thick Grips for Bicep & Tricep Bar Training - Ball Shape Fit Grips Sport spheres are roughly the same size as a baseball. The sphere shape allow you to instantly increase the outside diameter of dumbbells, curl bars, resistance bands, pull up bars, push up bars and cable attachments for thick bar (fat) training. Long-lasting, high-quality, dense non-slip military grade silicone that resists extreme wear and tear. Fit Grips have a unique cross-stitch grip designed that enables a safe and strong hold. Used by NFL players, MMA fighters, bodybuilders, cross-fitters, power-lifters and many pro athletes. The ergonomic round design distributes force to the natural shape of the human grip. By increasing the size of the bar you will notice more isolation on your forearms, biceps and triceps. The outside diameter is 2.5 inches. Inside diameter is 1 inch which fits on most standard and olympic bars. LIFETIME WARRANTY - By Core Prodigy - Fitness Equipment Leader