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.
把它放入一个15升的容器中，大约三加仑， 它就可以冷却到冰点之上 高于冰点3度 在30度的环境中保持24小时，而且它很便宜。