Hey Raul,
Ive actually used them for almost everything
Balls , JCP, Bloods, Most Geckos, False Water Cobras etc... They work fine if you set them up right and keep and eye on them.. You can hook a Ranco up to them set the ranco to 90 degrees so if it goes over that it will shut the whole thing off and you can buy another huvobator... Its a cheap way to do it.
Obviously i dont use them anymore but i never had a problem with them (wouldnt cook Calico eggs in them...)