I bought 2 56 egg incubators like that and they were crap. Complete and utter crap.
One never worked properly (only ever had one egg hatch from it out of dozens) and the other was buggy as crap and stopped working after several months. If you find it crapping out on you, you can follow the Franken-bator articles in my signature to gut it and make it work with a conversion kit. They work much better now! I would only use them in a climate controlled environment or as a lock down incubator (when them embryos can stand more variable temps). I'm currently living in an old farmhouse and last year, the temp swings between night and day killed DOZENS of eggs I had in those incubators.