The K.1 Silicone Magnetic Balls from Laid. The purpose of the K.1 Silicone Magnetic Balls is to provide the most flexible and fun way to do pelvic floor and vaginal strength exercises. Small enough for everyone to insert with ease, they combine to provide a larger shape within that you may squeeze your pubococcygeus muscle group (PC-muscle) around. The idea is to be able to visualize the exercise you are attempting, for example moving the balls apart or even forming a straight line. The K.1 Silicone Magnetic Balls are made of steel and over-molded with body safe silicone making them easy to clean and hypoallergenic. Weighted sufficiently the balls do drop to the vagina opening with ease and can be taken out one ball at a time. The 2 smaller, black currant balls are magnetic and weigh 0.81 ounce each, the 2 larger weigh 1.27 ounces each. A set of 4 balls weighs a total of 3.8 ounces.