Random Orbital Sander Universal Conversion Disc with Hook and Lock backing converts 5-hole and 8-hole PSA (Pressure Sensitive Adhesive) Orbital and DA (dual action) sanders to Hook and Lock. Universal hole pattern, a one-size-fits-all design, fits all 5 and 8 hole PSA Orbital and DA sanders for fast and precise alignment. Premium hook and lock backing enables repeated attachment and removal of discs for a consistent secure connection. Universal Conversion Disc Backing provides a strong and secure bond between sander and conversion disc.