I am an incubator rookie. After I purchased a small, cheap incubator and was fairly successful, I knew I wanted something to hatch more eggs and to give me better odds with shipped or rare/expensive eggs. Sometimes I get super busy and I would slip in checking the humidity and didn't want to keep opening it to check it or add water. So when i saw this as an accessory for the hovabator genisis with automatic egg turner I had to get it and give it a shot. It runs within a couple degrees of the incubator reading and I only had to fill it once during the 21 days. I hatched 10/14 lavender orpington, 10/15 silkie and 8 out of 24 serama shipped eggs in the middle of summer which I was very happy with. You just set it and basically forget it. Great directions and so simple to assemble and set. A must have for people who love hatching eggs but want a more simplified approach.