The Balls Bolt Stroker is a masturbator created by NS Novelties. It's one of the few masturbators out there that is dual-ended. To use it, you obviously need a penis (or some penis-like attachment if you're just doing it for fun). Then you simply use it like any other masturbator: apply lube, insert, shake 'n bake. Since it's so oddly shaped, I don't see how it would be possible to use hands-free. It's pretty noisy; the sound it makes is more akin to other strokers of its kind and less like the "hiss-schlick" sound you get from a Fleshlight. Since there are no electronic parts, it can easily be used in the shower or wherever you like. It's pretty stretchy and has 2 different-sized openings so it can accommodate guys of all shapes and sizes.

The toy is made of TPE which isn't the safest material out there, but one of the safest ones for masturbators at a 6 on the EF safety scale. It's very plush and soft. It has no taste, but the manufactures did seem to use a fruity perfume as an additive to the TPE as it has a permanent (?) fruity smell. I actually really like it and think it's pretty cool that it smells so good. TPE is porous, however, and you cannot boil or bleach it. The outside of the toy is very smooth and is covered in some sort of powder to make the toy feel more velvety. The manufacturers really got the powder in there well as I have not been able to get it out completely. The internal texture is a series of bumps and ridges of varying size. The toy has 2 different openings and one is larger than the other.

The toy consists of two big blue balls with an opening on either side. It's extremely discreet and I don't think many people would know what it is without handling it for a while. It could easily be mistaken for a weird double stress ball. Also if you've suddenly gone blind or something and have no idea which side is which, the balls are actually slightly different sizes.
The internal size is very nice. The big opening is good for foreplay as it's not very tight at all and is good for light soft play, while the small opening is pretty tight and is great for the main event. I'm pretty average and I fit both ends pretty easily, so even if you're really big or really small, you'll probably still get enjoyment from this toy.
The first thing I noticed about this toy was how big it was. It seemed a lot smaller from the picture on EF, but these are the actual measurements according to the EF product page:

Color: Blue
Length: 5 3/4"
Fits up to: Any size
Width: 2 3/4"
Vaginal depth: 5 1/2"
Weight: 1 lb

At that size it's not very easy to hide, but it is very discreet and the openings have no mouth or vagina or butthole outer texture (very similar to the Fleshlight Pure).

The toy has no electronic parts and does not vibrate, but it does perform very, very well. Both ends give very different sensations even though they're still the same texture, just coming from different directions. The toy is pretty noisy so it would be a good idea to use it alone. It's not as stimulating as my Count Cockula, but it still gets the job done, from either end.

Another benefit of the double-ended tube design is that it makes cleanup a breeze. The TPE material of this toy is a lot tougher than my fleshlight sleeve and to clean it, I simply turn it inside out and clean it with ordinary soap and water. Then I dry it with a paper towel, and store it in its original packaging. It's actually a lot more low-maintenance than my Fleshlight. Since it's TPE, please only use silicone or water-based lubes with it.

One thing that NS Novelties toys are apparently famous for is their amazing packaging. The package is a large cardboard box, with the toy inside contained in a plastic tray. The box is very, very sturdy and contains tons and tons of information. The most indiscreet thing on the box is a picture of the internal texture. If I gifted people sex toys, I'd simply wrap this up and send it.