Cotton qcs???...

[Ethan diy]

Hi all I was wondering where I can get cotton for my Qcs coil for the cubis atomizer I've never replaced cotton or built a coil but I saw on YouTube how to replace it in the cubis Pro atomizer qcs coil however I don't know where to get the cotton is it something specific or do I have to trim it to size I would really appreciate some knowledge on this subject if anyone has to share thank you so much