Ra-flect Radiant Barrier (Ultra) Laser Perforated 48" x 250' (1000sf) Perforated 48" by 250' (1000 Sq. Ft.) Roll 95% Reflectivity 0.05 Emissivity Thickness: 4 Mills Shear/Tear Strength: (Machine Direction) 10.47 lbs. of force & 17.84 lbs. of force (Cross Direction)