if its an old wood one. Leahy manufactured it. I have a single tray 1 . I use it to incubate, and hatch in a old sportsman 1250. I keep a pan pie pan of water in mine.It just fits reg egg turner, so Sets 42 and will hold about 35 to 40 on humidity with a pie pan of water. I used the orginal wafer, but upgraded to one of those 15.00 china elctronics. I love it. I do not hatch in it. But it does have the sliding top vent and 4- 1/2 in holes in the bottom. I duct taped 2 of the bottom shut , plus the bottom joints between the boards. I leave the top slide open about 1/4 inch and did put an old puter fan in . It is kinda set and forget. I fill the pie pan about every 3 days and even with the old wafer would hold temp great. I am hatching some right now that were in this old gal for 18 days. I set another 42 Friday morning. I just thought the electonic themostat might give me a bit better temp control, I set mine up with 2 like the sportman. Left the wafer set at 101 and have my electronic set at 99.6.If you get it figure out, you will love this ol gal. I have an old 300 egg Des Moines hot air kerosene burner. This will be my next project. Convert it to electric, update with electronic. and I am thinking home made roll x type turners.3 tray. 100 per week, hatch in my hatcher. I love these old incy's