Normally, I'm skeptical of anything with "smart" in the name. Smart cars, smart water... if it's so smart, wouldn't we be able to tell without having it in the name? But in the case of Fun Factory's Smartballs Teneo Duo, I saw them in a video about female ejaculaton, so that certainly piqued my interest.

The Smartballs arrived packaged in an appropriately sized box with a little plastic clamshell, an product booklet, and a water-based lube sample packet (Fun Factory's Toy Fluid). The clamshell doesn't stay closed on it's own and would not be practical for storage. The balls come in a number of different color combinations to suit your personal tastes, and I love the classic black and white on mine. With their criss-crossed texture they kinda look like alien testicles on a string. The majority of the casing has a velvety matte finish and the small color contrasting sections are glossy.

In the palm of the hand they feel very substantial and much much firmer than I expected. If you shake them, you can feel and hear a small hard ball move around in the outer silicone casing. The big difference between the Duo and the Uno is weight, with the Duo weighing twice as much (3 oz) as the Uno (1.5 oz). People who are completely new to PC excercise or recovering from injury might want to opt for the Uno. The Duo's weight and classic two ball design is great those looking for something more than regular kegels.

The two balls are connected by a thin round band. I would feel more comfortable if I knew whether or not this is a silicone-coated cord or just a little strip of silicone, but thus far I've been unable to find that information. It seems strong enough and has a little stretch, but it's not stretchy and springy like the longer silicone retrieval cord at the end of the second ball. I am probably being overtly cautious and have no reason to believe that the balls won't stay together, but it would still just be nice to know. This is a very popular toy and somebody out there has to have the answer.

The insertable portion (the balls and the connecting strip) is about 3.75" and the retrieval cord (unstretched) is about 3.5". Each ball is 1.5" in diameter and has very little give. I'm not the most accommodating person and will have to work up to using them myself, but I have yet to met a partner who hasn't been able to take them. It would be smart of Fun Factory to offer some sizing options. If they were a little bit squishy it would be easier, but then they wouldn't be as stimulating. Even with plenty of water-based lube (no silicone!) they are easy to retain due to the texture.

There are so many awesome ways to use Smartballs. You don't even have to think about excercise while wearing them if you don't want to. The internal movement of the smaller balls will shift the weight distribution and trick your PC muscles into working out. You can squeeze them if you want, but you'll get stronger no matter what. You can add extra resistance by tugging on the retrieval cord while simultaneously trying to hold them in. The sensation they provide will differ based on your body type, but they have proved capable of stimulating the g-spot and are really fun to have in during oral sex. It can be tough to concentrate on giving oral and thrusting a toy at the same time, but tugging on a string is simple and suprisingly powerful.

I love the fact that Smartballs can be used for both excercise and play. Stronger PC muscles have a whole host of benefits, including stronger orgasms, so they will improve your sex life even if you don't use them during sex. They are also discreet enough to wear under clothing, unlike some other PC weights. They would not be a smart choice for anal play. Even though they have a retrieval cord, they lack a flared base.

The exterior of this toy is silicone, a very smart material for these purposes. They can be boiled, wiped with diluted bleach, or run through a soapless dishwasher cycle. They are easy to throw in a bag for travel, but they will attract lint. Anyone who knows what Ben Wa balls are will probably be able to guess that this is a sex toy. Beware of fake Smartballs on the market and buy from a trusted source (like EF!) to make sure you get the real thing. I see no reason why they won't go the distance and last through many workouts, orgasms, and squirtfests to come.

Love these things! Especially how much fun they add to oral.

That said, a couple new points:

(1) Running with them in isn't the best idea. At best it's kinda stressful, at worst it can be painful.

(2) The lube that comes with them (Toy Fluid) has glycerin, which can cause yeast infections in some women.

(3) DO NOT boil them. After more research I have concluded that boiling is just too risky. Not sure about the top rack of the dishwasher either. Stick with diluted bleach if you want to clean thoroughly for sharing.