Resin over resin bonded. Provides a stronger, heat and moisture resistant bond that better utilizes the abrasive grains. The cotton cloth provides a tougher, durable backing for longer life. J-flex cloth provides a higher degree of flexibility to conform to contoured part. Cosntructed Using a Resin over Resin Bond That Provides a Stronger, Heat and Moisture Resistant Bond That Better Utilizes the Abrasive Grains.