Metal Worx Series from Pipedream Products made from Stainless Steel. Ben Wa Balls Medium are great to use in conjunction with Kegel exercises or during sex to intensify orgasm. How to use: a woman inserts the balls and will become aroused as they move while she moves or walks around. Also builds muscle strength.The balls are weighted so that you have to contract your muscles to hold them in. This is not only helpful with strengthening vaginal muscles but also helps strengthen bladder control. Use with intercourse or when doing your Kegel exercise routine. Although Ben Wa balls may sometimes be listed as vibrating they do not vibrate in a traditional way but through kinetic energy. Each Metal Worx masterpiece comes in a discreet storage case you can use to store your toy after use. The premium steel pieces are great for temperature play, stick them in the freezer to cool things down, or place them in a bowl of hot water to heat things up. Cleanup is a snap after the fun with Pipedream Toy Cleaner and warm water. Avoid abrasive cleansers to prevent scratching. Features and Functions: Cools, Warms, Phthalates Free, Waterproof. Material: Steel. Country of origin China. Package dimensions: Depth 3.00 inches, Width 4.00 inches, Height 3.25 inches. Packaged weight 8.60 ounces. Package type Storage case.