I take a dime and trace it on the bottom of a small cardboard box. Then I cut the circle out, and place the egg on top of the hole. Small LED flashlight underneath the box works like a charm, as it doesn't produce heat like the candle that came with my incubator. Last night was lock down for my bobwhite eggs, and for the first time, I was clearly able to see a defined air cell. Then I was bummed out at how easy they were to view compared to Cots; made me wish I had candled at day 12 or so to view the veins and development of the chick inside. I should have took a picture of my set up.