The application is child's play.

Step 1:

Fill up the measuring cup with boiling water!
The measuring cup is included in delivery.
Always fill the measuring cup up to the mark. (rim approx. 4 mm
  under the opening = 210 ml, see example).

Stesp 2: 

Screw the Cool Twister onto the measuring cup!

Step 3: 

Turn the Cool Twister around and place it directly onto the baby bottle!
Always let the entire amount of water run into the bottle.
In case you need less water, pour away the extra amount
  (=> use the measuring scale of the baby bottle!)
When developing the Cool Twister, we referred to the instructions
   and maximum amounts recommended by the powder manufacturers
   (in case you need more water for your bottle, you can just  
   pour some extra hot water through the Cool Twister
   after the 210ml ran through and you unscrewed the measuring cup.)

Operating mode with sectional view
By means of the following animated film, you can see how the Cool Twister works. [WMV-Format ca. 9 MB].
Animated film with cross-section of the Cool Twister

Film of the functional principle of the heat exchange
In order to illustrate the functional principle, the cooling down process was recorded with a thermographic camera. Experience the cooling down process in real-time, whereby 100 degrees hot water is cooled down to 50 degrees Celsius.
  Functional principle- Thermographic camera film [WMV-Format ca. 8 MB]

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