The Metal Worx Ben Wa Balls are made of stainless steel. Stainless steel is a safe material, rating a 9/10 on Eden's safety scale. They are nonporous, phthalate free, and can be completely sterilized. The small spheres are hard and completely smooth and shiny. They are polished enough to capture a clear reflection.
It is possible to include temperature play with the balls. This adds an additional sensory dimension to the workout. An easy way to warm them is to place them in a warm mug of water. They can also be warmed in a heating pad or electric blanket, although this takes more time. Being metal, they should never be microwaved. To cool, place in a mug of ice water or leave in the refrigerator for a short time.
The medium balls are 1 inch in diameter, and each ball weighs 1.1 oz. They are about the size of a shooter marble, but heavier than a standard marble. Metal Worx does sell a smaller set at .75 inch. Those are an advanced set, as the smaller balls would be even more difficult to hold in than the larger 1 inch set. Some systems of kegel exercisers have balls that are connected and also have a retrieval cord. This set is two individual balls without any connecting cords or retrieval cords. Because they are not connected, either one ball or both can be used.
The balls are small and smooth enough to be inserted easily with lube. Any type of lube, whether water, silicone, or oil, may be used.
Ben Wa balls are small and travel easily. Keep in mind that, being metal, they will set off metal detectors. You don't want to be wearing them at the airport.
With regular use, the Ben Wa Balls will strengthen the pelvic floor muscles, increasing sexual satisfaction and bladder control. The key, of course, is to use them regularly to develop strong vaginal muscles. They won't work if left to sit in their box. A dab of lube makes these a snap to insert. They are comfortable to wear.
Women may have one of two separate issues with them. Some women may not have enough muscle control to wear these. They may find that they slip right out while standing up. A good solution would be to use them while rocking for a few weeks, until sufficient muscle control is gained. Other women may have the opposite problem. They can hold them in just fine, but it may be difficult to remove them. Keep in mind, there is no way to lose them in the vagina. Just relax and then use the muscles to push them out. The second ball might be more difficult to remove since it is farther back in the vagina.
The balls can be cleaned with soap and water, a toy cleaner, or a 10% bleach solution. They could also be boiled or placed in the dishwasher. The only thing you should not use is abrasive cleaners that would mar and scratch the metal.
They can be stored in the included durable case. The case resembles a trunk with a snap latch. A foam inset lines the inside. The Ben Wa balls rest easily when not in use. The top of the trunk clearly labels the contents as Ben Wa balls so, although wonderful storage, it is not discreet.
I have used these every day for two weeks. I have found them to be comfortable and easy to use. After inserting, I have rocked in a chair for 15 to 20 minutes and then continued to wear them for up to 30 minutes while moving around. In the first week, I had to reinsert at least once every session. In the second week, I was able to hold them in better without too much slippage. I haven't yet noticed any difference in actual love making, but I am sure I will as I continue to use them.