Threaded screw-in lid with rubber O-ring combines to seal out water - the O-ring fits snuggly around the cover to create a tight seal.
If you already have an existing RWO inspection port on your boat and are in need of a replacement, these ports will fit.
Made in England to metric (millimeters) standards.
|Fasteners (mm)||3mm FH (x6)|
|Note||Nominal Diameter: 4" (100 mm)|