Times have changed since I wrote this article. A much better device than the one described below is the Diamo, from Lovense. It's substantially more expensive than this simple device, but it is much more versatile, powerful, and longer lasting. It operates standalone or is controlled from a computer or cell phone by yourself or a third party. But the following article might prove interesting if you're on a budget or just interested in the history of such things.
During your training, Dom de Luxury may employ a device she calls the "Mind Control Ring." A highly effective training tool, once switched on, it is impossible to do anything but what she asks of you.
These devices are relatively inexpensive but can be used only once or twice before their battery runs out. There is no easy way to replace the battery, so you must buy a new one. Replacing them a few times a month or a week adds up. You would be better off spending that money on makeup, clothes, and shoes or paying for more training with Dom de Luxury.
There are articles on the web that explain how to change the battery. It involves disassembling the vibrator and is tricky and error-prone. There is a much better way. And not only is it cheaper, but it delivers a much more intense experience.
The two big names in vibrators are Durex and Trojan. The Trojan ring is slightly more expensive but easier to modify. Purchase a Trojan mind control ring from your local drug store (probably cheapest) or from here. Then purchase a 'vibrating bullet'. You can get them from here or from a local shop. You will also want to get a pack of batteries. I bought these from Amazon, and I think they are a great buy. They last a long time and are very inexpensive.
The rest is elementary. Use the Trojan ring until the device it came with runs out of juice. Then remove the vibrating mechanism from the rubber holder (gently!) and throw it away. Put a battery in the bullet, then slide the bullet into the place formerly occupied by the Trojan device. That's it.
Occasionally, the bullet may not start vibrating. In my experience, this is always because the cap is not tightened enough or is on slightly crooked. And, of course, you will occasionally have to replace the Trojan "ring." Once or twice a year, at most, in my experience.
I hope this will be helpful in your training. Let me hear how it's going for you!