Special 3m hi-temp closed-cell foam tape with an adhesive tape on one side is used by sticking the tape to a dry vacuum packed boiliable bag. A temperature probe can then be carefully inserted into the product at it 's thickest point. the special foam tape allows the bag to keep it's vacuum once the temperature probe has been inserted. Then the whole package along with the temperature probe is placed in the water bath. this allows you to monitor the cooking process. Once you have monitored the process a few times then you can make notes on how long it takes to reach temperature for certain cuts and thicknesses of meats. You could then add additional minutes for a margin of safety.