This is so simple and it works great! You will need: 3 sandwich size ziploc bags 2 rubberbands or hairties First fill a ziploc bag about 1/4 with water. Then zip it closed and try to get all the air out. Then for spill safety put it in another bag. If you have OCD (like me) Put those into yet another bag. Triple bag it, and try to get air out of each bag as you go. Then lay your probe from your thermometer in the middle section of the bags of water and roll it up tucking in the zipper part. Then put 2 hairties or rubberbands on each end to secure it. Then place it seam side down in the incubator and there you have it!