I am writing this primarily as a service to those poor, benighted souls who received this expecting to insert some batteries, fire it right up, and have some fun in the first 30 seconds. Not so fast. Sexual pleasure may best be preceded by a few moments of contemplation spent in trying to figure out just how to get this thing working.
I'm a boyfriend who bought this for a girlfriend. Since she is neither practiced nor patient with electrical devices, I decided to set up the vibrator ahead of time. In addition to the vibrator, you will need two AA batteries. Don't bother looking for any instructions. There are none. Don't bother looking for any markings on the vibrator case indicating how to put the batteries in or where the on/off switch is. There are minimal markings. Truth be told, these things really aren't necessary once you have a few handy hints. Hence my comments.
Initially, I stuck the batteries in and tried to evoke some vibrations. Nada. I reversed the batteries. Nada. I discovered that the twist-off bottom for the battery compartment could also be twisted, and on the plastic it says this is for speed control, so I twisted it quite a bit. Nada. I tried three sets of batteries, just in case, all to no avail. This took 15 minutes as I became more and more frustrated, resolving to write a one-star review about another DOA device. Then my fumbling produced vibrations, quite by accident. It turned out that I had tightened the compartment cover so that it was snug, and it turned out to be too snug to work.
So, here's how to set up this little gizmo: put the batteries in with a +/- or -/+ pattern showing (rather than a +/+ or -/- pattern). Wrap some tape around the threads and snip off any excess. This should allow you to put the battery compartment cover on snugly but not too snugly. Turn the vibrator on by twisting the bottom. Speed it up by twisting it some more.
Aside from the cheesy electrical connections, the vibrator actually seems to be of fairly decent quality for a $13 device. The plastic seemed hard at first, but it's actually more of a flexibly stiff and slightly spongy nature, which is probably best for its intended use. Complaints about smell seem exaggerated--the vibrator has a fairly normal and slight smell of plastic, but it is not overwhelming and is hardly a sign of toxicity (my girlfriend has a keener sense of smell than I, and she agrees with this assessment). Other complaints concern the lack of 14 speeds; the motor appears to be continuously variable, and while it is true that the bottom dial does not have 14 distinct points, the speed can in fact be adjusted enough to suit anyone. The motor's power should also be enough for almost anyone. The device is fairly quiet while running. Some reviewers have complained that the vibrator is just too large to, well, I guess to fit in comfortably. So I measured the circumference at the widest point. It's 4.75 inches, which just happens to be the average circumference of a fully erect you-know-what (cf. Wikipedia). Granted, it may not be quite as warm, soft, or flexible as a you-know-what, but...at least now you have some objective information for judging size relative to yourself.
Does it work well? Yes, but its effectiveness will depend on the specific use. As a maxi-vibrator for women, it is best intended for solo use. For this it works very well. For sex with a partner, it also can work well as a way for a guy to stimulate his partner. I will note, however, that it is difficult in such circumstances to know by feel if the vibrator is stimulating the right spot, and so coaching from the lady is very helpful. For actual intercourse (i.e., with penetration), the vibrator is less useful because of space limitations (except for reverse mounts, so to speak), and a mini-vibrator is much better for this purpose. My girlfriend thought that it could also be used on me, but it is decidedly not suited to this purpose.
I hope this helps.