2.No more middle of the night water level alarms: Sous vide balls are to minimize the effect of heat loss and water evaporation, allow you cook water for hours on end without ever having to re-fill. Due to the exposure between the water and air, water hardly evaporates during the cooking process. 1.Food grade materrial: free, made of Approved Food Safe material polyethylene. Reusable and can be used for sous vide cooking safely. Lower loss during cooking. Provide healthier, and more convenient cooking . 3.No more lids: Acts as lid to reduce splashing hazard and allows easy access to all shapes and sizes contents. 4.Drying and storing easily: Packed in practical mesh bag, facilitates the drying process after use and for easy storage. You could put all the balls in and hang up the bag in somewhere and without mess.