Let your designs shine—with building bricks that really light up! Our LED builders let you create bright, beautiful structures…without the wires. Just turn on the base, start stacking and watch your design come to life—right before your eyes! Set includes 36 building bricks, a base and a USB cable. Base is powered by the USB cable or 3 “AAA” batteries (not included). Bricks measure 1 1/4" x 1 1/4".