NE555 LED Christmas Tree Decoration Red and Green LED Blinking PCB Crcuit Ornaments Soldering Kit with LED Lights Flashing Lights Soldering Practice Board for STEM Educational Valentine Day. This kit is a basic soldering kit designed to help in teaching the fundamentals of through-hole soldering and circuit design. It combines education and practicality, enabling users to learn while creating a beautiful decoration. The kit displays a beautiful alternation of red and green lights and requires 2 CR2032 batteries. It can be hung not only on Christmas trees but also on backpacks, windowsills, and more, making it a great gift and a versatile decoration. The kit is ideal for beginners, school experiments, parent-child teaching, and friends who love handcrafts and science.