What is this blue mesh tube thing in the Rema TT 06 patch kit used for? I own an (old-ish) Rema TT 06 patch kit. The contents look like this:



Notice the blue tube-like thing under the left box. In the part list on the manufacturer's site, I couldn't find any mention of that thing (http://www.rematiptop.com/part.php?pid=56&amp;cid=5&amp;sid=4, which is also the source of the image).

Is is basically a short tube of mesh-like, flexible material. What is it used for?
Looking at manufacturers site I found repair kit with 'mysterious' blue mesh listed as "Cartridge freeze protector". 

It is supposed to be put over the cartridge (like in this picture) to prevent skin irritation/burn because CO2 gets very cold when discharged.