Two Hova bator 1602-N both different?

[SilkieTime]

I have two hova bator 1602-N and both of them are different one has a insert between the top half and the bottom half that is 1 1/2 inchs thick that looks like a picture frame. Maybe to make it taller for bigger eggs and the other one does not. Do I need this insert to hatch small eggs or not? I have a tubo air flo kit and turner for both. I got them used from different places. Really could use some help with this one.

 

[hinkjc]

In the older model, the expander was sold separately to increase the height for larger eggs at hatch. It is not necessary for small eggs. More for turkeys, geese, ducks that could reach to the top and touch the heating coil.

 

[SilkieTime]

Thank you for the help. That was the answer I was looking for.