I saw at target this little light in the clearance isle. $2.45 it even came with battery. So I figured for 2 bucks worth a try. Wow! I just put it over the top in the bator and checked 42 eggs in a snap. Even worked for my green and blue eggs. My marans were hard to tell. Super duper dark hehe. I am thrilled at how well it worked and to think I was going to buy one of those candlers on Ebay that are costly.