The Smartballs Teneo Duo by Fun Factory is a vaginal exerciser used for increasing PC muscle strength and overall vaginal tone. This is the double ball version of the Teneo Uno. It can be used as an advanced exerciser after trying the Uno for beginners. Women with strengthened PC (pelvic floor) muscles are likely to have a better sex life and have an easier time having orgasms. These muscles when toned can also minimize problems with urinary leakage. There is a ball inside of the Smartballs which moves and "vibrates" when you move around. These vibrations stimulate the PC muscles to start contracting.

This heavier set of Smartballs, is much more noticeable internally for me than the Uno was. Smartballs are very discreet and travel friendly. No one can tell when you're wearing them and they pack up very nicely. These can be worn vaginally during anal sex for an increase in stimulation for both your partner and yourself. Obviously these should not be used anally since there is only a retrieval cord and no safe flared base.

The Teneo Duo is made of silicone which rates a 10 on Eden's safety scale. The texture is ribbed and velvety. The balls feel hard because of the underlying plastic, but the silicone covering is less firm and has a lot of drag. This ribbed texture stimulates you internally especially when the internal ball starts vibrating. The connector between the Smartballs is firm enough to aid in insertion while still maintaining some flexibility. Duo is completely waterproof and is made of hypo-allergenic food-grade materials. It is also free of phthalates, latex, and is nonporous. Duo has no discernible taste or odor.

Teneo Duo is 7 1/4" long with an insertable length of 7 1/4". The circumference measures 4 3/4" with a diameter of 1 1/2" and weighs 0.3 lb. The ball is inserted and there is a retrieval cord which hangs out 3 1/2" beyond the end of the Duo. I found this to be too long and it bothered me slightly while wearing it. The base of Duo has an indentation which is supposed to make inserting with one finger easy. This is a design change from Fun Factory's original Smartballs. The connector in between the Smartballs also helps it stay rigid when inserting. The Duo also came with a sample of Toyfluid, a water based lubricant.

Duo can be very discreet and travel friendly. It takes up very little space and it completely unnoticeable when wearing. I think the Duo's size is more for intermediate or advanced Kegel exercisers. There is definitely more fullness when wearing the Duo. I could barely tell I had the Uno on when I tried it. It needs to fit correctly to stimulate the PC muscles to contract and this came closer for me than the Uno did. The design is not realistic at all. The Teneo Duo comes in a variety of color choices as seen on the product page.

Teneo Duo has a hands-free feature that sounded appealing to me when purchasing this product. Smartballs are designed to stimulate the PC muscles to contract while also providing pleasure during long-term wear. I definitely felt these more than the Uno. Every once in awhile I would move around and feel them move inside, almost a deep rumbly "vibration". It reminded me that I had them in, even though the effect was not super intense. It kept bringing my attention to my pelvic area and triggered my PC muscles. This worked better for me than Uno but the length was a bit much. The downside of feeling them inside was that they made me want to pee, it felt like they were pressing against my bladder. Taking them out was also challenging, I would suggest adequate lubrication. The Smartballs did not feel too large going in, but when removing they felt huge. If you plan on leaving these in for a longer period of time, use more lubricant than you think you need. Squatting down helped me get them out easier than other positions.

Caring for Teneo Duo is quite simple. Soap and water cleansing or using a toy cleaner is fine for daily use but the Duo can be sterilized in the dishwasher or be boiled for a few minutes. Water based lubricant is the safest choice for it since silicone lubes may possibly degrade silicone toys. I store my the Duo in its clamshell package.

Teneo Duo arrived in a red and silver box with a clear plastic window which displays the ball. The plastic clamshell inside houses the ball. The back of the box has a magnetic fold out which has additional information. The packaging, although not discreet, looks clean and provides a lot of information about the product. I like to use my clamshell plastic package for storage, it keeps my Smartballs from getting tangled with other toys.