This device is rechargeable via USB (or a USB/AC adapter) with the included charging cord. It has a self-sealing charging port in which I was able to insert the charger with no difficulties.
According to the instructions (and the listing on the EdenFantasys website), it lasts for up to 2 hours on high and 3 hours on low. I can't verify that as I haven't timed my uses, but I haven't had to charge it since my initial charging when I received it, and I've used it maybe 3 times I think? I also have not experienced a drop in power yet (due to low battery).
To charge the device, simply plug the charging cord into the self-sealing charging port and the USB port on your computer or an AC/USB adapter. While charging, the control button blinks; when full, the button lights up solid.
According to the instructions, it takes about 70 minutes to charge. I didn't time it, but when I plugged it in, it was ready by the time I expected it to be ready.
To turn it on or cycle between options, press the control button briefly. Each brief press will step to the next option in the cycle.
To turn it off, press and hold the control button for 2-3 seconds.
This design makes for ease of changing patterns even in the middle of use, and you can't accidentally turn it off (as some reviews on more expensive devices indicated that those devices could).
The 7 available patterns are:
* Low
* Medium
* High
* Steady pulses (2-3 pulses per second)
* Pulses in a short-long-short pattern repeated
* "Revving", starts low, and smoothly speeds up to high over approximately 2 seconds then goes back to low again
* Pulses in a pattern of six extra-short pulses followed by a long pulse repeated
All pulse patterns pulse on the high setting rather than medium or low.
While I'm not sure of the difference between "rumbly" and "buzzy" (I've read these descriptions in other reviews), I can tell you that while I've been writing this review I've been turning it on and off and cycling through the patterns and I felt the vibrations all through my fingers. When I put it against a stiff or tight muscle, I feel it the deepest on low setting; also, at this point in the review, my hands are feeling a bit tingly even when I'm not handling the device.
When used as intended, it provided stimulation not only through contact on the upper vulva and clitoris during intercourse, but also vibrated my husband's penis to the point that I could feel it inside. It felt quite lovely and added a new, pleasurable dimension to our lovemaking.
With regard to sound (bees), it's not the quietest device in the world; however, it's a lot quieter than I am during sex. It can barely be heard from another room with the door open. I'm pretty sure that a closed door would be effective for preventing others from hearing it -- unless you put it down on a surface, especially a hard one. Then it will make rather more noise and possibly be noticeable in a quiet house.
Would have been nice to have a pic with the ring stretched out to see how stretchy it is. Many men like the ring around the scrotum and penis. Or a pic around a dildo with balls. Of course you would have to have one laying around or borrow one.
Great job !