Fastflex™ is a closed-cell polyethylene foam joint filler that is supplied with a convenient tear-off strip. When the tear–off strip is removed, it creates a void for the sealant in order to prevent surface cracking. Fastflex is available in continuous lengths in wall thicknesses of 3/8” and ½” and widths from 1” through 8”. Features: Tear-off strip incorporated to create voide for sealants Natural Bond Breaker Use with cold-applied sealants Water resistant Lightweight Inert Recyclable Reusable Clean product Made in USA Does product contain a hazardous material: No Does your Product Contain any Volatile Organic Compounds: No Contains Chemical: No Contains Pesticide: No Material Type:: Closed-cell, Polyethylene