Watertight, overlapping cover conceals fasteners for a clean, modern look. Three separate sealing rings assure a watertight closure. Twist threads are non-jamming, self-cleaning, and lift the center for easy removal. High impact, marine quality plastic with UV inhibitors. Designed for Non-traffic areas: bulkheads, cockpit walls, and cabin sides. ID 5" OD 7" Hole 5-1/2" Color Black