They have a main wafer and then a backup wafer in case the main one goes out. I keep a couple extra on hand because I have 4 incubators. I also use 2 thermometers and a hygrometer in each incubator. As far as I know the wafers stay good if they are not used, but I have had the experience of...
I got my temps regulated and haven't had to adjust it in 4 years, so to say they are good incubators is an understatement. AND the parts are readily available from the manufacturer for any repairs that may need to be done down the road. You won't beat that deal anywhere and I think you will be...
I have 4 of those, 3 wafer and 1 digital. I prefer the wafer myself. I bought all of mine used and gave $400 apiece. Does the incubator have the automatic turner?