Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: how many buttons does the mouse have
Document: I got this for a Mac mini I purchased for my son. Love how it mimics the Apple keyboard with volume and eject buttons, plus the addition of a power button. The mouse is functional, not as nice as an Apple, but at this price point it is as good as any PC offering.
I really like this keyboard/mouse combo, especially when it was $2 cheaper with the mouse than without. In fact, the mouse is one of the best parts. It's a little smaller than many mice, but works really really well. The keyboard itself is very noisy, compared to many other keyboards, but works really great, particularly for fast typing.
I love the feel of the keyboard, but I was having problems with my mouse losing its bluetooth connection many times per day, and great difficulty connecting this keyboard in the morning. After hours on the phone to Apple, we found that the BTKey was causing the problems. I emailed Macally, and they tell me the 32-bit driver is not compatible with Lion. Great! They said they may update it someday, but will not give me an answer as to when.
Also, if this keyboard goes bad in a few years, I know that it won't cost that much to replace.It's important to note that you can get the keyboard as a standalone for a few dollars less but the fact you can find this Macally keyboard/mouse combo for around $21-$26 is fantastic!But I needed a keyboard that gives me the speed and the right feel for the many articles, interviews and reviews I work on each day and week.
good alternative to the apple products that are much more expensive - good layout and good battery life - wrong sequence on volume buttons
It has volumn control buttons on it which will adjust the volumn on both your computer and the Ipad. It  has the lights that will indicate if Cap lock is on, when it is pairing with Bluetooth, and when the battery is low.
Has a power button but only turns computer off, not on. The Ecomouse has a good feel and has good resolution and control, but the software didn't work. There is no way to program the buttons. Still it is good buy for the money.
The manufacturer description says it all - good construction & budget conscious! This combo is excellent at only $27.99, and contrary to others' experience, I did not have to install any drivers to get the Eject, Volume, and Power Switch buttons to work - I just plugged it it and went!
And let me say that I hesitated on buying this keyboard at first because some people went on about the buttons not feeling right or had lag. I didn't have any lag issues. Nor did I have problems using the keyboard. I was typing quickly like I was with my Mac slim keyboard but in no way was it like the white Mac keyboard with the harder buttons.
Buttons are concave, so unlike my Apple Mac keyboard, the letters won't be easily scratched off.After attaching the keyboard, it asked you to press the key next to the shift buttons and immediately, the keyboard was detected. Audio buttons worked, power button on the keyboard worked. My Mac using 10.7 OS detected the keyboard with no problems whatsoever.
Answer: It kind of looks like one big button but this is a two button mouse. I've used it on both Macs and Windows PCs. You get the "right-click" behavior without using the control key.