SUNKEE Round 40x20mm/1.57"x0.79" N38 Rare Earth strong magnet, 1 4/7" Diameter 4/5" Thickness Disc Neodymium Magnet Material: ROUND Neodymium Magnets Grade:N52 Dimension: Dimension:40x20mm / 1.57"x0.79" Max Operating Temperature: 80C/176F Please read the manual before use, or you can contact us if you feel sth wrong Caution: strong magnets are brittle; strong magnet could pinch your fingers badly; if you allow two magnets attract together, it may cracks and the chips could hurt your eyes.