Yoni Egg

An egg-shaped stone (usually jade, quartz, or obsidian) intended to be inserted into the vagina. These are associated with neotantra, and have various uses, including for kegel exercises (which help to tone the vaginal muscles) or pelvic floor training. Caution should be taken when using yoni eggs as porous materials such as stone can retain bacteria and prolonged contraction may also adversely effect the muscles.