3M 20908-120-UFS SandBlaster Ultra Flexible Sanding Sponge, 4.5-Inch x 2.5-Inch x 1-Inch, 120 Grit, Medium Lasts 5X Longer than 3M conventional sanding sheets Channels dust away from sanding surface Use pattern side for detail/contour sanding Use regular side for flat sanding Made of premium aluminum oxide mineral