1High intensity egg candling lamp to control egg development, helps observe the growth of fertilized eggs. 2After the incubator has been running for a few days, it is possible to scan the eggs with a bright light to see inside the shells, allow you to see the fertilized eggs showing a dark spot and veins. 3Powered by 3 AAA batteries(not included), light weight, compact and portable design, easy and convenient to use. 4The egg candling flash light provides bright and cold light, for ultra safe lighting of your eggs. 5The cold light tester is not only for someone who wants to hatch eggs, it is also suitable for children and students to learn the incubation process. Suitable for fun class or school lab.