It’s a small buzzer created for the LilyPad system. IT allows different noises to be made using 2 I/O pins. Change the frequency and see the results, it has a volume that can be heard from a pocket, which is very suitable.
Note that the buzzer CAN’T be washed, or else it’ll be damaged, also, put both I/O pins to LOW when you’re not using the buzzer, since it acts as a short to ground when not being actively drived.
Please note: This is an inductive buzzer meaning that is will act as a short to ground if you are not actively driving it. We recommend you put both I/O pins to low (0V) when the buzzer is not used. Also, it's come to our attention that washing these buzzers will damage them. Until we've figured out a solution to this, avoid washing any portion of your project that contains one of these buzzers.
LilyPad is a wearable e-textile technology developed by Leah Buechley and cooperatively designed by Leah and SparkFun. Each LilyPad was creatively designed to have large connecting pads to allow them to be sewn into clothing. Various input, output, power, and sensor boards are available. They're even washable!
[Product pictures and description are courtesy of Sparkfun.com]