Squeeze these foam plugs into the ends of pipe or conduit to fill the space around cables. When heated, they expand to fill any gaps left if the cables shrink or melt. They’re tested to ASTM and UL standards for stopping the spread of smoke and flames. Cut holes in these plugs to pass cables through, or use them to block the ends of unused pipe or conduit. Once they’re installed, you can paint them without losing fire protection.