Smart Attic Tent Insulation Kit for Attic Entry - 25&rdquo; x 54&rdquo; x 9&rdquo; Improve HVAC Efficiency SMART ATTIC TENT - Attic entryway insulation kit helps improve HVAC efficiency. INSULATION - 5mm (1/4 inch) closed cell polyethylene foam sandwiched between pure aluminum on both sides. ENERGY EFFICIENT - R-Value 15.67, Reduce up to 94% of heat at your attic door. SIMPLE INSTALLATION - Easy to handle and install, no special tools required. ENVIRONMENTALLY FRIENDLY - Non-toxic, non-carcinogenic.