Universal hole pattern, a one-size-fits-all design (fits all 5 and 8-hole sanders) for fast and precise alignment; premium ceramic grain blend, a superior quality formulation designed for fast material removal and long sanding life; premium Hook and Lock backing enables repeated attachment and removal of discs for a consistent secure connection; Clog-SHIELD, a proprietary blend of grinding agents that reduce pitch build-up and clogging; for orbital and DA sanders in wood, metal and plastics.