Bosch 25-Pack 3-3/4" 80 Grit Detail Sander Abrasive Triangles are designed for sanding plywood, hardwoods, and softwoods. They are also designed for hard-to-reach areas and use a hook and loop attachment to the tool. These sanding triangles are great for fast removal of material during the sanding process. They have a hook and loop backing that attaches to standard detail sanding pads.