Underlay 3mm Rubber

Thickness :3.2 mm
Water resistance : waterproof
(Moisture can not penetrate closed cell membrane)
water absorption : 0.003 lbs/cubic feet
Density : 3.50 lbs per cubic feet
Sq Ft per Roll : 200 Sq. Ft.
Thermal Conductivity : 0.25 BTU/hour/sq.in. 
Fire resistance : UL 94 HFI,F,A,R,25.83
IIC Rating : 72db 
STC Rating  ：73db
(condominium  approved)