Sold in a pack of 10 LEDs (picture may show more, each lot you buy is 10 LEDs).
Oh boy, these things are ridiculously small for an RGB led, the same size as a normal 1206 led, that's 3.2mm by 1.6mm, but it has a red, a green and a blue die squeezed in there with 4 pads instead of 2!
Common cathode, the cathode "pin" is marked with a green dot on the bottom.
You will need a steady hand that's for sure, the separation between the pads is very thin.
But, it's all worth it for the beauty of such a small RGB led I'm sure!
I don't have any specs, but would shoot for about 20mA as maximum. Remember to use a current limiting resistor, no resistor = instantly destroyed LED in most cases.