The board includes 10 APA102 addressable LEDs controlled by the on-board ATtiny85. Includes 10 APA102C LEDs controlled by the aforementioned ATtiny85. APA102C LEDs operate just like most addressable LEDs over a two-wire interface. The board ties that interface to the ATTiny85 and operates both the IC and LEDs at 3.3V logic. Board Dimensions