I've got my first batch of eggs in the bator and tried my first candling with a flashlight cupping my hand around the light and eggs. It worked ok but all I could really see was a blob in the eggs, so I decided I needed something better. I have a streamlight scorpion flashlight thats small and puts out good light, I'm sure there are plenty of other flashlight options that will work fine. I cut about a 2" piece of bicycle innertube and slid it over the end of the light. I just set the light on top of the egg and the rubber innertube seals against the egg and really lights it up. Took less than 5 minutes to make and innertubes are only a couple bucks.