This is a great holiday gadget . . . as fun to build as it is to display! It's also an excellent confidence-builder for learning and/or reinforcing the essential hobby skill of soldering. Complete, unassembled electronic kit includes pre-cut Christmas tree circuit board, 16 blinking LEDs and instructions. Very low power consumption; Max: 4 mA. Requires one 9V battery (not included) to operate. Dimensions: 2.4 inches wide x 4.0 inches tall x 1.0 inch deep.