There are the silicon rubber tube dampers that probably best brace a tube at least in 2 locations corresponding to the micas. My question is do you really need them? I have played with them on my preamp tubes but haven't noticed a difference. They look cool but not nearly as jewel like as Andy's Vacuum Tube services dampers but these are brass jackets inner silicone rings and are gold plated just for looks. See Positive-feedback this month.
