Geisha Magnetic Balls are easy to use and come in a set of four with varying weights. This includes two pink balls weighing 27 g (0.95 oz) and two black balls at 15 g (0.55 oz). The exercise begins with one black ball on a silicone string, gradually increasing the weight by adding one ball at a time, similar to gym workouts. The Geisha Magnetic Balls offer seven workout levels, ranging from 15 g (0.55 oz) to 84 g (3 oz). Experienced users can train without the string. Designed with human anatomy in mind, these balls are made from 100% soft medical silicone and come with a one-year warranty.