You put it into a 15-liter vessel, about three gallons, and it'll cool it down to just above freezing -- three degrees above freezing -- for 24 hours in a 30 degree C environment. It's really cheap.
１５リットルの容器に入れて 氷点の少し上くらいまでに冷却します ３０度の環境で ２４時間冷却効果が持続します。とても安く、