A shiny, simply and pleasurably functional take on the classic ben wa ball, the Silver Balls from Nasstoys combines a weighty, kegel strengthening design with an arousing feel. Your eyes will be immediately drawn to the uniquely ergonomic shape of this tool, each of the two balls is perfectly spherical with a super sleek ABS plastic body; they're perfectly shaped to fit inside you comfortably and pleasurably, sitting precisely in place for maximum muscle strengthening. The weights inside jiggle and jump with movement, creating a naturally vibrating effect that feels amazing, encouraging you to keep them in, and in turn toning up the muscles that are responsible for orgasm and sexual control. A sturdy string holds the balls together in the middle, and forms a long tail which acts as a withdrawal cord. Thanks to the slick, non porous plastic, clean-up is easy once you're finished; a wipe with warm soapy water or toy cleaner will do the trick. Compatible with any type of lubricant.