The Smartballs Teneo Duo by Fun Factory is a pair of connected vaginal balls intended to aid in exercising a woman's internal muscles. Insertable vaginal exercisers such as these are designed to stimulate a woman to use her Kegel muscles, which is believed to increase tightness, promote stronger orgasms, and even mitigate health problems ranging from painful menstrual cramps to overactive bladder and incontinence.

To use this item, you simply insert it into your vagina and wear it about. You can use them at home, at the office, in class, at the grocery store...One of the great joys of these balls is the thrill of wearing them around without anyone knowing. As you go about your day, the motion of the weights inside of the balls stimulates your body internally, aiding in completing your daily exercises. Kegel exercises can benefit many women and are especially helpful for women with weakened vaginal muscles caused by childbirth and aging, among other things. However, pregnant women and those who have experienced UTIs (urinary tract infections) should discuss the use of vaginal exercisers with their doctors first. I have also heard that women who regularly use tampons or diaphragms should also refrain from using these. Check with your doctor if you have any doubts.

Theoretically, these could be inserted anally if you were so inclined, since they have a retrieval cord and they can be fully sterilized. Fun Factory advises against it, as well as against inserting them into your nose or ears! Personally, I wouldn't risk it. If you choose to do so, make sure you either cover them with a condom or sterilize them between uses - be it vaginally, anally, aurally, or nasally.

The Teneo Duo is made of firm, high-quality silicone, which has a very slightly sweet, familiar smell to it and little to no taste. It feels velvety soft. The surface of the balls have some raised swoops and divots on them that I feel actually detract somewhat from the experience. They are already a bit large and the matte surface and the additional texture make it incrementally less enjoyable and more difficult to insert. My guess is that the balls of the Teneo Duo are textured to give them a little bit more grip and prevent them from slipping out of users with weaker internal muscles. Using a bit of water-based lubricant will definitely ease insertion, especially since they're often being inserted for a practical purpose, when the user may not necessarily be incredibly aroused. Even still, the texture and size of these balls may be better suited to more experienced users of vaginal exercisers. I love the feel of the material, but the texture would be better if it were slightly less pronounced.

I really love the design of this exerciser. It's beautiful and it comes in a wide range of colors that will appeal to just about anyone. The slightly oblong spheres are textured/ribbed and measure about 1 1/2" in diameter. The first ball is connected to the second by a 1/2" long flexible cord, similar to the retrieval loop. The second ball features a little hollow located between the two points where the retrieval loop connects to the ball. Snuggling your fingertip into place is incredibly helpful for keeping a good grip on a lubed up exerciser as you press it gently inside of you. Removing the Duo can be a slightly uncomfortable process due to its size and texture. Take hold of the retrieval loop and pull gently and steadily, while bearing down with those well-exercised internal muscles of yours.

The full length of the Teneo Duo is 7 1/2". You can pull the cord up and loop it over the top ball, keeping it in a compact little bundle which makes it very travel friendly. The cheerful colors lend a discreet appearance to this futuristic-looking item. The Duo's insertable length of 3 1/2-4" doesn't sound like much, but for wearing about, standing, walking, running, bending, climbing stairs, or whatever else one may need to do in the course of the day...some women may find the Teneo Duo rather uncomfortable. I tried it repeatedly in the interest of writing this review, but I can only wear it for about ten minutes before the pressure at my entrance becomes irritating bordering on painful. The unfortunate truth is that I cannot comfortably accommodate the length of this exerciser. Cutting the length of the connecting cord in half may have given enough space or it's possible that the balls themselves need to be a touch smaller all around. I wish that Fun Factory had decided to make them just a shade shorter when they updated the design from the Original Smartballs. See the "Personal Comments" section for a detailed comparison.

This is a beautifully designed exerciser that will work absolute wonders for the women that find it a comfortable fit. Depending on how you position the balls inside of you, the cord may be somewhat annoying. I'm sure you would get used to it if you wore it for an extended period of time and went about your daily activities with it in. The motion of the internal weights rolling about inside of the balls is a wonderful, gentle feeling that made my muscles clench up almost involuntarily every time. While the pressure and fullness of the balls were definitely noticeable even when I was standing still, they're at their best when you are moving your body. Walk, wiggle, run, jog, climb stairs, dance, spin, shake your booty! You can feel the weights with even the slightest movement of your hips.

The Smartballs Teneo Duo is incredibly easy to clean. Its nooks and crannies are shallow enough that they do not gather bodily fluids. You can simply wipe the balls down with toy cleanser or wipes or rinse them with water and antibacterial soap. To fully sterilize the Duo, you can put it in the top rack of your dishwasher or boil it.

These are small and easy to store. It does not attract lint or dust. I keep mine in the boxes they came in, just because they're so neat, but they can be stored in a drawer, in a sock, in a small drawstring bag...The retrieval loop can even double as a cord for you to hang the balls up. Be careful not to store them with toys made of Jelly as the Silicone material can react badly, resulting in damage to one or both toys. Similarly, use only water-based lubricants with this item to avoid ruining it.

The packaging for this toy is mindfully and tastefully designed. It is a red and silver cardboard box, about 3.5x5x2", with minimal patterns and images on it. The Teneo Duo is nestled inside of a plastic clamshell within of the box, which can be viewed through an opening on one side of the box. The other side has two magnetized doors bearing an image of a woman's hand holding the balls. Opening the first door reveals a description of the Teneo Duo in a number of languages (German, English, French, and Spanish). Opening the second door affords another view of the toy inside, as well as a diagram denoting the item's design elements. The box and the manual inside tell the buyer more about the Fun Factory company, the item and its use. They even include symbols indicating that you should only insert this item into your vagina and not into your ears, nose, or anus.

The box also includes a brochure with pictures of Fun Factory's vast array of products, as well as a small sample packet of the company's water-based lubricant, Toyfluid, intended for use with their many high-quality silicone sex toys.

As compared to the Original Smartballs:

Material - Original Smartballs were made of Elastomed, while the Smartballs Teneo Duo is made of Silicone. A definite improvement since you can now sterilize them!
Size - The Original Smartballs were slightly smaller in diameter, measuring in at 1 3/8", while the Teneo Duo measures in at 1 1/2" in diameter. Unfortunately, they are identical in length, making them too long for some users.
Design - The Smartballs Teneo Duo has a much more sturdy, built-in retrieval cord, as well as a hollow in which to place your finger for insertion. Although the Original Smartballs lacked the improved cord and the finger hollow, they were not textured the way the Duo is, making them somewhat easier to insert.
-Performance: Truthfully, they feel about the same inside. They are subtle, but very stimulating.

As compared to the Smartballs Teneo Uno:

Material - Both are made of matte, high-quality silicone.
Size - The balls themselves are identical in size, but the Teneo Uno is only one ball, while the Duo is two. The Uno is only about 1 3/4" of insertable length. The Duo measures 4" of insertable length when stretched out, or about 3 1/2" with the attachment flexed.
Design - The Uno has a slightly shorter, slightly narrower cord than the Duo, which makes it more stretchy. It has held up over the years and has never broken, but the Duo's cord is significantly sturdier. Unfortunately, it's also more noticeable when you're wearing it.
Performance - The movement of the weight in the Uno is not noticeable at all for me when it is inserted. The movement of the weights in the Duo are definitely noticeable. Subtle, yet pleasing.