Double Layer Foam Pad. 

• Ultralight closed cell foam pad offers comfort as well as insulation under any sleeping bag
• Impervious to cold, will not crack or become brittle at temperatures of -60 °F (-50 °C)
• Thicker foam for extra comfort and insulation
• BP9

Measures:  20" x 72" x 1/2" (69 x 183 x 1.3cm)