If you have ever had difficulty in making a decision then this kit may be just the answer you've been looking for. When you depress a small on board switch a bright green LED and a bright red LED begin to alternately flash. As soon as you release the button, one of the LEDs stays on indicating the decision. Red means no and green means yes. Fun to use and fun to build. Uses a CMOS IC and operates on one 9V battery (not included). Size of PC board: 1 3/8" x 1 7/8". Complete with all parts, PC board and instructions. Skill Level 1.