I don't remember. It should be in the incubator info, or you can find it online. Maybe 15th knows without looking it up.
The humidity is important all the way through, but especially as they hatch. If the membrane dries out, they get stuck.
Michael, if you do chicks, try a warming plate for your brooder. I used one last year instead of a light and it was way better + I didn't have the fire risk.