Uxcell 140x20x15mm Lighting Fixture Mounting Bracket Ceiling Light Plate 2 Set

What is this? This ceiling light plate can be mounted on the ceiling floor to hang or hold the chandeliers ceiling lamps. Widely used on home office bookstore or other somewhere. Are there any advantages of the product? Made of galvanized iron material good rust resistance long service life. Fasteners like screw and nut will help to fix the chandelier on the ceiling wall firmly. How to use it? Easy to use just screw this ceiling light plate into a round ceiling light base. What should I notice? Please check the size before buying.