Both the cowls and the rings are made of heavy duty, investment cast, stainless steel. These cowls can revolve and be removed without any tools simply by loosening the upper ring by hand.
A Monel mosquito screen and a solid stainless steel cover plate to close off the cowl ventilator can be purchased as options. See Accessory Products, below.
Comes complete with threaded ring nut and male mounting ring.
• Red or white interiors
• Three sizes available
• 6.9"² - 19"² free flow area
How these vents are mounted...
These cowl vents are consist of a "deck" ring, and a cowl with a loose collar ring (aka "nut"). The "deck" ring is permanently mounted to the top of a dorade box, and the cowl is then placed on the deck ring and secured by tightening the collar ring.
The deck mounting ring is secured with (4) flat head fasteners, and has coarse external threads.
The female-threaded collar ring is loose on the cowl, but captured by a flat flange ring which is screwed to the bottom of the cowl with 3 screws (see image). The cowl is placed on the deck ring, and the collar ring is then turned down by hand or with the supplied deck key until tight. The collar ring can be loosened at any time to allow the cowl to be rotated as necessary.