Ergonomically designed to tighten and tone pelvic muscles6 interchangeable weights for a fully customizable workout regimenSingle and double Kegel ball holder with easy retrieval cordsHygienically superior. body safe SiliconeKegel exercise guide from Dr. Sherry includedDimensions:Variable Weight Kegel Balls: 20. 25. 30. 35. 40. 45 gOverall (Single Ball Holder): 4 in.Overall (Double Ball Holder): 6 in.Each Ball: 1.25 x 1 in.Package: 5.5 x 9.5 x 2.5 in.