I ordered this for my Farm Innovators Pro 4200 which came with everything but a liner. Water leaks out the bottom without a liner even tho the unit has a plastic shell. The shape of the water channels in the bottom is different but it still fits and works perfectly. I ordered an extra just to have on hand. Wonder why all incubators don't have a liner. It is a "must have"

I got my incubator used and it did not have this. After using it with and without it is a MUST.