Their wine cooler contains a freezer insert that will keep your wine chilled for up to 4 hours. A warm bottle of wine placed in a fully frozen insert will be chilled to 55°F in thirty minutes. The insert will not allow the wine to be chilled below 42°F. The cooler is designed to work with 750ml bottles of wine having a maximum diameter of 3.5 inches and a maximum height of 13 inches. The contents of the cooler insert are non-toxic, water-based gel and should be frozen 4-6 hours before use. For longer gatherings, we recommend keeping a spare insert in the freezer.