This is a Dunn-Rite Anchor Cap for their 2-3/8 Inch O.D. Anchor Sleeve. The top of the cap measures 6 inches in diameter. Designed for Dunn-Rite pool basketball and volleyball games that use their 1.90 inch O.D. brass anchor. This anchor cap will work in most 1.90 inch O.D. anchor sleeves.
The anchor caps are sold individually. The picture depicts both sides of the cap.