Unlike the more common vent that is secured with six stainless screws, this vent is secured to the dorade box by way of a plastic ring which is included with the vent. The ring has a large 4" diameter female thread which threads onto the matching male threaded ring (included with your purchase) on deck. This makes the vent easily removable.
Perhaps more important, the large threaded ring makes it easy to loosen the cowl vent by hand. Rotate it into the wind for better ventilation or to face aft if a lot of water is coming over the deck. Once the collar is retightened by hand, the vent is held securely in its new position. The original vents do not have this feature.
This version is made from a new, improved silicone material which will withstand exposure to UV radiation better than the original version.
installation included two vents per boat. We sell them signally each so it is possible to replace only one vent or two as needed.