Bondo® Fiberglass Mat provides added strength for repairs requiring extra reinforcement. Use Bondo Fiberglass Mat with Bondo Fiberglass Resin for repairs on almost any surface including metal fiberglass and wood. This easy to form non-woven fiberglass mat has interlocking and randomly intertwined strands of fiberglass which provide the ability to bridge holes and gaps in the repair surface. Slightly thicker than Bondo Fiberglass Cloth Bondo Fiberglass Mat is recommended when additional strength is required on more severe repairs like larger holes and cracks and is perfect for repairs made on use on automobiles boats tubs showers sinks pools hot tubs and more.