ITEM HAS A 2.58 IN RADIUS INTERIOR OPENING; MEASURES 6.00 IN HIGH AND 7.20 IN WIDE AT THE TOP AND BOTTOM; MADE FROM SILICONE RUBBER IMPREGNATED 2 PLY/MIN/ GLASS COTH PER MIL-C-9084 COATED WITH AN ALUMINIZED REFLECTIVE MATERIAL; INSULATION MATERIAL IS .19 IN THICK; COVER EXTERNAL SURFACE TEMP NOT TO EXCEED 450 DEG F WHEN USED WITH THE BLEED AIR DUCT SYSTEM AIR TEMP AT 800 DEG F AND A MAX AMBIENT AIR TEMP OF 350 DEG F WITH NATURAL CONVECTION; COVER IS REMOVABLE AND FLUID PROOF.