Excellent quality heavy duty “Nairn” brand Australian made nylon inspection ports with rubber “O” ring lid seals. Most ports are available black or white – with clear, white or black lids. Ports with synthetic storage bags are available in 5″ and 6″ sizes. All ports other than 8″ are screw in type (8″ is pry-out type). The size quoted is the inside hole size of the port.