•The inner and outer layers of the cooler are made of 18/8 (304) food-grade stainless steel, and the middle is a double-layered vacuum.
•Put the blue gel bottle in the freezer for 6-8H before use. After taking it out， the gel bottle will slowly release the coldness, Put it in the vacuum cooler and keep cold for up to 48H in an outdoor environment of 86℉(30℃).
•If using a white ice water bottle, it can be extended by 12H, total keep cool for up to 60H