Fun Factory Smartballs Duo

I like my vag muscles to get wrekt. My interest in kegel balls stems from days during my period, when flexing my pubococcygeus (what PC stands for, apparently) muscles very temporarily relieved menstrual pain. I was also the kind of kid who would pee and then stop and pee and then stop for fun in the bathroom. I had no idea what kegel balls were until I read Epiphora singing the praises of Luna Beads. I was also very into the idea of being able to flex vag muscles around a partner’s dick, but I waited to actually buy anything because I thought things that were designed to give me orgasms were better than things that only might give me stronger orgasms eventually.

If Epiphora was the first checkpoint on my kegel journey, Elle Chase was the next. I managed to win a set of Noir Luna Beads1I am not linking to these beads directly because I don’t support Lelo, the company that makes them. You can find equivalent (and better) kegel balls made by other brands. and I wore them all over the place for a couple weeks. My third (and currently final) checkpoint was learning about how many different kinds of kegel balls there actually are during my time working at the Pleasure Chest. I chose the Fun Factory Smartballs Duo for a lot of reasons and after just over a year of owning them, I’m glad I did.


The Smartballs Duo consists of two 1.4” diameter balls, connected by silicone, measuring 3.7” long total, with a silicone handle on one end. The first ball is slightly more tapered to help with insertion, and both balls have hard ABS plastic “windows” (or inserts) on either side of them. They come in White & Indian Red, White & Grape, Raspberry & Black, and Black (with grey inserts). Between the handle is Fun Factory’s logo indented into the silicone. Kegel balls are meant to strengthen vaginal PC muscles, which can help with incontinence (feeling the need to pee), menstrual pain, toning muscles after childbirth, and they can help make orgasms stronger.


Kegel balls like the Smartballs Duo are worn inside the vagina for a period of time and there are a few ways to interact with them. If you prefer to be productive, actively clenching around kegel balls throughout the day is like lifting weights. Some folks like to clench when they hit red lights when driving, during commercials when watching TV, or anytime a particularly blustery teacher says “um” during a class. If however, you are incredibly lazy like me, you can just leave them in as you go about your daily business to eventually have a stronger vag. Luckily there are a variety of kegel balls on the market which cater to most vag-ercise persuasions.

As a beginner kegel-er, it is easier to start out with lighter and larger kegel balls. A larger surface area means they are easier to hold inside your body (rather than them falling out anytime you get up) and  your body will be more aware of them so it’s easier to grip them subconsciously. Smaller and heavier balls are something to work up to with more refined PC muscles.2I am not a gynecologist though, so if you’d like to start with small and heavy, you do you. I prefer and recommend kegel balls that come with some retrieval method such as a silicone handle since I don’t want to go spelunking in my vag whenever I have to pee or decide I’m done wearing my kegel balls.

Most kegel balls also have lil rolly bits inside them. The more rolly and rumbly these are,3Rolly/rumbliness determined by shaking them. the more likely your body will notice them. The more your body notices them, the more likely you will clench and grip in response. I like to think of this as tricking my vag into exercising. The Smartballs Duo does just the trick for me. A lot of folks really dislike the seams in the Smartballs, but these are a very intentional decision by Fun Factory. After rigorous testing and several designs, they found that it’s easier to feel the rolly-ness of their kegel balls with the plastic “window.” I have no idea why this is the way it is, but in my Very Scientific shaking experiments, I do think the Smartballs are the rolliest balls made of non-porous materials.4Luna beads use (porous) string as a handle.

An image of several hand weights, leading up to the Fun Factory Smart Balls Duo


When I wear the Smartballs Duo, I feel them wiggling especially well if I roll side to side or if I walk somewhere with a purpose. I have no idea if wearing them has made my PC muscles stronger (for this, I really want the Minna k-Goal to measure my PC strength) or my periods less painful but at least I feel like I’m being more productive with my vag during a Netflix binge. However, the Smartballs Duo are larger than your average kegel balls so they’re not really a set-and-forget kind of thing. I don’t consider myself a size queen but I also don’t often need a warm up when using larger toys vaginally. With the Smartballs Duo (and some water based lube), I insert them and then walk around for a bit because usually I haven’t inserted them far enough so the lower ball painfully tries to exit my vagina.

Wearing one ball in and one ball out is also a valid way to wear the Smartballs Duo, especially if you want to work up to the larger size of both inside you. I don’t want to worry about what pants I’m wearing and whether or not they show a kegel ball, so I keep both balls inside me whenever I use them. When they’re all the way inside, they are kind of noticeable because of the size. If I’m working out or moving a lot, I notice them more than if I’m just sitting around or not doing too much. There have been times when I’ve completely forgotten about them inside me.

I take my Duo out when I use the bathroom (though in theory you can pee and maybe poop with them in) and rinse them before I reinsert. This rinsing also means that there’s basically no time for any vag gunk to dry in the seams of the “windows”5Though if it did, I have an old sanitized toothbrush that I keep specifically for sex toy seam cleaning. If bigger toys are more difficult/painful, Fun Factory also makes a single-balled version, the Smartball Uno which features the same splendid rumbliness as the Duo. The Duo sells for $29.99 and the Uno for $24.99. While you can get body-safe kegel balls for slightly cheaper, I have yet to find any that are comparably rumbly for this price.


Purchase them from Early to Bed, SheVibe, or The Stockroom (uno, duo).


Smartballs (Uno and Duo) are made with silicone and ABS plastic and have no electrical components. They can be washed with soap and water, cleaned with a 10% bleach solution, or boiled for 3-5 minutes.

Smartballs include silicone, which can bond with silicone based lube. I recommend using a water based lube so you don’t run the risk of ruining your toy.


  • Rumbly
  • Great for lazy kegel-ers
  • Competitive pricing
  • Body safe materials
  • Reputable company


  • Larger size can be uncomfortable
  • Seams can collect gunk
  • Not the cheapest on the market

This toy was purchased with my own money, and I am not receiving anything in exchange for this review. There are affiliate links included. If you like this blog and want to support the work I do, please consider clearing your cookies and purchasing through my affiliate links.


1 I am not linking to these beads directly because I don’t support Lelo, the company that makes them. You can find equivalent (and better) kegel balls made by other brands.
2 I am not a gynecologist though, so if you’d like to start with small and heavy, you do you.
3 Rolly/rumbliness determined by shaking them.
4 Luna beads use (porous) string as a handle.
5 Though if it did, I have an old sanitized toothbrush that I keep specifically for sex toy seam cleaning.