Smartballs Teneo duo - vaginal balls by Fun Factory - review by chicmichiw

Huge Purple Balls

I don't plan on ever using the Duo again -- they're rough, large and painful for me. If you know you need a larger size, then these are for you. The Duo is thoughtfully designed, made of body-safe materials and quite attractive, but the entire point of this toy is to be a Kegel exerciser, which I found impossible. Even as a sex toy, Duo pleases only slightly.
Silicone outer and cord
Duotone balls are easily felt
Rough texture
Too large for most
Rating by reviewer:
extremely useful review


The Smartballs Teneo Duo from Fun Factory has only one purpose: vaginal exercise and one hopeful side effect, sexual pleasure due to the presence of smaller balls that can freely move inside the larger balls. The smaller balls are the key to achieving pleasure from the Duo while you move around such as doing housework or light exercise.

The Teneo Duo is for the female-bodied only! The Duo is not for anal use despite the presence of a retrieval cord. The Fun Factory manual additionally recommends that the Duo only be used for 3 hours at a time.

I'm not sure what the consensus about Kegel ball size or whether you should use one or two is, but I'm operating under the assumption that a larger ball and more balls are for beginners or ladies who have a larger canal size or are less toned. The idea is to insert the balls and keep the balls inside your vaginal canal by flexing your PC muscles, otherwise they should fall out. The Teneo Duo is a large toy and is, as the name implies, two balls.
Comp to vibe and uno

There's always the Teneo Uno if you need only one ball. I own both, so I'll be comparing the two throughout my review.
  • Who / How / What
    [ ? ]
    Who might this product be best for? How is it best used? What are the best circumstances or situations for using this product?
    • Solo
  • Where
    [ ? ]
    Where / what types of places can this product be used?
    • Anywhere
  • Body / part areas
    [ ? ]
    What areas on the body can this product be used / what areas does it stimulate best?
    • Kegels

Material / Texture

The Duo is very firm, unsqueezable and rattles in your hand. The two balls are connected by a thin but substantial amount of silicone. This connector region is both pliable, yet firm enough for insertion.


The Smartballs Teneo Duo are supposedly 100% silicone, which has a net-like design to it over the two balls-- it looks almost like the balls are netted in silicone with plastic underneath. It's just a part of the design. The white (in my color selection) areas do seem like hard plastic to me, but there's no way to get under the 'netting'. I think this design is primarily for texture.

I love Fun Factory's silicone, which is always featured in a great variety of unique colors. It feels like good quality silicone. Even upon first opening the package, the Duo had no smell or taste.

I imagine the smaller, 'duotone' balls inside the Smartballs are plastic and they're undoubtedly hard -- you can hear them rattling around! While in use, I can't hear them inside of me and multiple tests at the gym tell me that others can't, either.
    • No odor

Design / Shape / Size

length in hand
Unfortunately, the large size and firm material mean that you'll need a lot of lube and I would recommend being moderately to very aroused while inserting them, as the texture is a bit rough feeling. The balls mostly spherical and don't taper at the tip, which means insertion will feel abrupt. When you succeed with the first ball, inserting the second will require some pushing on the first ball, which may feel uncomfortable, a bit like a pinch and sliding feeling. Fun Factory did include a small finger divot in the back of the second ball, which made insertion just slightly easier. Unfortunately, it feels nothing like phallic penetration or really any kind of comfortable penetration, due to the varied, waving surfaces.
texture close up

back and logo

The size, as I'll explain more below, is just too big for me. If the Uno is at your limit, like it is for me, then don't even consider the Duo.

Even though I love the aesthetic of the Duo, I just can't use this toy as a Kegel exerciser. As a very intense penetrative toy, it's at least interesting. I wouldn't write the Duo off as an unorthodox sex toy.

Comparing the Uno and Duo:
What I loved about the Uno as a sex toy is impossible in the Duo, again related to size. The Uno managed to naturally find the curve of my G-spot and even though the single ball is the same measurement as the balls on the Duo, one ball is infinitely more comfortable. While the hard surface of the Uno served to stimulate my G-spot, the Duo can't find it in the first place and starts to rub against my walls, which hurts. The Duo is also long enough to be crammed against my cervix, which isn't comfortable. What a shame.
    • Whimsical / artistic


Once inserted, I was truly overcome by the sensation of fullness. It was an incredible, intense feeling and actually had me shaking. The combination of the duo tone balls and the size of the outer balls meant that it was impossible to ignore the toy -- this is definitely not a toy I'd put in and then forget as I go about my day.

Three problems:
For the first ten minutes, I moved about gingerly. I was so scared I'd feel some kind of internal pinch if the balls somehow moved in a strange way, but luckily no such thing happened. As I did some light yoga, I at least stopped fearing for my privates. The rumbling sensation was pleasant at least.

But my problem with the Duo is three-fold: first, they were huge. They held me open in a both uncomfortable and air-pushing way, which was I positively hate. Second, they were honestly too big and rough for me to really do my Kegel exercises around them. Somewhere between excessive discomfort and being totally overwhelmed by sensation, I tried to take them out.

Now here's the third problem and it's really an additional hurdle of fear: taking them out hurts. I've read other recommendations to lay down while you remove them, but I can't. I'd be exclusively pulling on the cord, which doesn't appeal to me. As graceful as this sounds, I'd recommend a squat and then give painful birth to this guys. Jeez. The popping sensation really doesn't help either. I'm not at all satisfied this aspect of the toy.
    • Easily felt duo-tone balls

Care and Maintenance

At least the Duo is easy to clean. After I caught my breath from removing them, all I had to do was use warm soap and water. The areas to pay attention to while cleaning are: between the balls, the divot in the second ball and some of the deeper ridges, near the contrasting color regions.

Since the Duo is silicone on the surface of the balls and most notably, the cord, it could stand 20 - 60 seconds of boiling if you so desire. Since the Duo does not have any motorized parts, the dishwasher is also an option If you find you use the Duo or any other Kegel balls frequently and for long periods of time, you should take good care of them so as not the introduce bacteria into your body.

Due to the size of the Duo, some kind of lubricant is essential. The best way, I found, is to apply lubricant to both yourself and all over the toy, even a bit of the cord, where it might be inside of you. Silicone lubes are not compatible with the Duo, but a long-lasting water-based lube like Sliquid or JO would do the trick nicely. If you'll be wearing the Duo for a considerable time period and while unaroused, lubricant will definitely help to keep things comfortable.

I still love Fun Factory's packaging -- Duo came in a gold-toned box with a red interior and a cradling trough for the Duo to lay in. The manual is neatly tucked into the lid in its own sleeve. The Teneo Uno has the exact same packaging, and the collector in me is pretty pleased with the matching boxes. A descriptive sleeve goes around the entire box and features a picture of the toy inside. It's not necessary to keep it and diminishes its discreetness, as it has a picture of a woman's torso and a pictoral representation of where it goes. I kept mine just so I could tell the Uno and Duo apart.

Uno and duo comparison

In box
    • Easy to clean
    • Easy to store
Follow-up commentary
Nope! I wish this had worked out. These guys are too big and scratchy.

Despite liking the additional movement that two balls affords me, I've actually been using the Teneo Uno more. The Uno is more comfortable, obviously smaller and you still get a decent amount of duo-tone inner ball sensation.

My recommendation? Get the Teneo Uno from the get-go and don't bother with the Duo.
This content is the opinion of the submitting contributor and is not endorsed by
Become a Reviewer. Get free toys. Enjoy Special Deals
Do you like this review?
  • Freyja9
    Great review, thanks!
  • shnsmth6
    thank you
  • Lady of the Lab
    Very helpful, too bad they don't come in a smaller version (like the Lelo mini set).
  • chicmichiw
    @Lady of the Lab, I would love that. I hear that it's important for the ball to be sizeable just so that the inner ball has something to rattle around in, but these were just too big. I'm definitely lining up the Luna minis, though...
  • PeaceToTheMiddleEast
    Those things look huge as heck I would not want to do vaginal exercise with those. Thanks for sharing!
  • anndolce
    Thanks for the review! I was contemplating these as I have the Luna balls, but after seeing how large these are in your hand, I think I'll pass.
  • KinkyKatieJames
    Now that I see these in your hand, I don't think I can handle them!
  • kristina0121
    thanks for the review
  • MrsHouseWife
    Thanks for the review. Might look at something smaller
  • cowboywill87
    Excellent review
  • Pumpk1nPatch
    I like the Uno, which is exactly the same weight as the duo.
  • sweisb4100
    Thanks for the comparison photos
  • chebellezza
    It's important to read many reviews. I am definitely happy with my purchase of Duo, and I like the feeling of fullness. Your review was fair, honest, and full of helpful photos. Thanks.
  • ginainohio78
    great review thanks
  • rainford
    great review
  • oftheunicorn
    Those look huge in your hand! Wow!
  • cowboywill87
    Thanks for the review, good job!
  • marshmallow
Thank you for viewing Smartballs Teneo duo – vaginal balls review page!