DeWalt Hook & Loop Velcro Backing Base Pad D26441
The Backing Pad is what holds the sandpaper onto the machine. Because this uses Hook & Loop technology, its grabbing power decays the more you swap out your sandpaper, meaning that your paper can become loose and fall off. It is good practice to change these every so often.
PLEASE NOTE: This is just the velcro pad, not the plastic carrier that this fits onto.
Please see suitable models below: