Flared Galvalume collar to prevent chain wear or chaffing. One piece, weld-free construction and corrosion resiCOLLAR, MOORING BUOY, 1 7/8 X stance you can rely on to last and last. Fits 1-7/8 inch diameter (2 inch nominal) collar/spindle openings. Galvalume steel alloy has 10X the corrosion resistance of hot-dipped galvanized steel.