Henry 3 ft. W X 65 ft. L Fiberglass Self-Adhesive Shingle Underlayment Blue

Waterproofing underlayment. Composed of a high tack rubberized asphalt, coated on a non-woven glass fiber mat. Lower surface has a silicone release paper or film backing. Used at eaves, valleys, flashings and on low-slope applications to provide watertig.