For each of the [LPD8806](https://www.adafruit.com/datasheets/lpd8806%20english.pdf), I am unable to figure out what should be the voltage levels of the Data In (DI) and Clock In (CI) pins? 

I am trying to use this individually addressable [LED Strip here](https://www.adafruit.com/products/306).

I know that VDD has to be 5V but cannot figure out the voltage level of the Data In (DI) and Clock In (CI) on each of the LPD8806s?

Or is anyone aware of a similar product of individually addressable LEDs?