NBR material: spheroidal Graphite cast iron with drain plugs (surface treatment: dakuromekki) with tightening: 8 mm Hex Hole Screws with screw plug, ho-ro-setto (tuber) standards: With this item is non-binding for single tube Φ 48.6 Hex Wrench is required. Insert the pipe part is 35 mm (excluding some items)