NOTE: This option is installed INSIDE of an already insulated Kitty Tube. Upgrade your new or existing Kitty Tube! The Kitty Tube Double Insulation Option doubles the R-Value of the Kitty Tube. Installation is easy and fits all previous modes of Kitty Tubes that have a “Kitty Tube” logo on the side. This accessory is perfect for 1-2 cats, as it creates a smaller space to keep your cats warmer in the winter. -All interior surfaces of the Double Insulation Liner have a Scratch Guard interior. - This assembly doubles the insulation value of the Kitty Tube. -The double insulation option also creates an important secondary insulated air space between the ceiling and the outer lid. -After installation, the same custom pet pillow, straw or pet heating pad will fit as normal. *Pictures are for illustration purposes. The Kitty Tube sold seperately. This is for the double insulation only-not to be used or confused with the main insulation set. The double insulation option MUST be used in conjunction with the main insulation. In the box: 1- wrapper for the walls, 1- interior top disc, 1- "T" bar to secure the double insulation wrapper to the main insulation wrapper.