25PCS Strong Magnets Countersunk Ring Rare Earth Neodymium 4mm hole

-Super strong Rare-Earth magnets - they are hard to break apart once they get stuck with each other. -Perfect for sticking notes on fridge doors. -Suitable for DIY projects, such as whiteboard fixing, adsorption of various steel parts. -Fixing tissue box on the roof, etc. -Material: Neodymium Magnet. -Diameter: 0.465-0.500inch -Thickness: 0.102-0.125inch -Hole Diameter: 4mm