My experience with the Shaker Vol. 4 wasn't a good one. My husband and I attempted to use it to aid in foreplay and it turned out to be a huge debacle.

The Shaker comes with a small packet of lube, which has the texture of snot. Nearly all the markings on the box, the Shaker itself, and the lube package are in Japanese. (I only know this because it says "Made in Japan" in English.) The only part, aside from country of origin, that's in English is the small section that says "Shaker Vol. 4 Simple Type Mens Hole."

When you unlock the outer tube, you notice it moves up and down, and also twists a bit. Don't let it fool you, there's not much point to that part.

If you remove the cap from the bottom of the tube, you'll find a flesh-colored insert made of TPR. On its own, the TPR is really sticky feeling. It doesn't feel like something you'd want anywhere near your penis. (My husband’s words.)

On the inside of the insert, there are some raised ridges in the same TPR material. The ridges could be useful, but only if you have about 8 inches of girth. Otherwise they're just there to look pretty.

Once you lube up (with water based lube) you'll find it's pretty easy to insert your penis; though you should be careful, because one wrong tug and the insert will separate from the outer tube. It won't go back in, no matter how hard you try.

If, for some reason you decide to separate the sections of the outer tube to attempt to clean the interior of the insert? Don't expect the insert to go back in and actually STAY in. To clean the inside of the insert, you have to turn it inside out and turning it inside out will separate it from the opening of the tube; like I said before, it won't go back in.

The insert on its own, it could be a useful masturbatory aid. The opening somewhat simulates an anus, and, according to my husband, feels pretty nice. But I wouldn't expect this product to work as is. There are some definite improvements that could be made.