2mm lights on 4.5 ft. silver string, takes 2 CR2032 batteries. (Included) Over 20 hours of bright light. Led lights are submersible in water, battery pack is not. Submersing it will reduce battery life by 7-8 hours. On and off switch. Small easy to hide battery case. Copper wire holds it's shape. Led lights are rated at 25 000 hours. Great for small houses, fountains, wreathes flower arraignments etc.