Type ‘D’ Stopping Plugs Type ‘D’ Stopping Plugs are used to seal unused cable gland or conduit entries in Ex approved Flameproof or Explosionproof enclosures, maintaining the hazardous location certification and the overall integrity of the installation.  D Plugs Type ‘U’ Stopping Plugs Type ‘U’ Stopping Plugs are used to seal unused cable gland or conduit entries in Ex approved Flameproof, Increased Safety or Explosionproof enclosures, maintaining the hazardous location certification and the overall integrity of the installation.  U Plugs