Can anyone tell me what that is for? I found it in the package with the laser when I wanted to dispose it. It says “package silicine adhesive sealant” and I have no idea what it’s for. 
Silicone is used to seal the electrical connections on the laser tube. On a new machine, they should be ok. It will be handy to have for when you replace your tube.
@Ulf_Stahmer Thank you. 
So hopefully I’m not going to need it soon. 
@Christoph_E sometime (like 4 me) the tube come in a different package and you have to install it yourself. but as far as I know everybody got 1 tube.