These are very interesting 5mm diffused RGB LEDs - instead of having 4 pins to control 3 LEDs, they have only two leads - power and ground. When powered, the LEDs perform a flashing effect with all the colors. There is no way to change the 'program' or rate, its burned into a little chip that is inside the LED itself.
The forward voltage of the whole LED is about 3.4VDC but you can drive them from
a coin cell like a CR2032 and they'll just be a little dimmer. We don't have a datasheet showing the current draw over different voltages and colors but at 3.4V its approx 20 mA and at 3.0V its approx 10mA.
Comes in a pack of 10 LEDs! Although the LEDs are all the same shape and have the same basic program, due to manufacturing variables they will not sync together - they'll slowly drift in and out of sync.