Check the listing for details. 25 50 100 Strong Magnets Countersunk Ring Rare Earth Neodymium 4mm hole. Condition: New. Listed at 12.99 USD. N35 Strong Countersunk Ring Magnets Hole 4mm Rare Earth Neodymium NOTE:Physical size is slightly different!! Features: Brand new and high quality. 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. It 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: 4mmN35 Strong Countersunk Ring Magnets Hole 4mm Rare Earth Neodymium NOTE:Physical size is slightly different!! Features: Brand new and high quality. 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. It 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