Having done the penlight and then the flashlight with a cardboard cutout for egg checking, I decided to moderninze and upgrade. This Cool-Lite works great, even on Marans eggs. Admittedly you may not get the definition of veining like you would with white-shelled eggs, but you can definitely see blobs in those chocolate eggs. What I really enjoy is that you can place this on the top of the eggs in the turning trays and see the embryos move in the spotlight (do in a very dark room). No risk of dropped eggs!