Freeman Hatch, 30" K Square. The 2400 Series Cast Aluminum Hatches are available in a variety of sizes and shapes. Standard models have a cast aluminum cover, aluminum dogging mechanism and the choice of cast aluminum, steel, galvanized steel or stainless steel rings based on model.
This has an Aluminum Deck and Knife Edge Seal.
Please refer to the PDF file that is attached in the 'Extras' tab for dimensions on the hatch.