Powerful Neodymium Magnet N52 50x30mm Round Neodymium Magnet Rare Earth Permanent Super Magnet Very Strong Magnet
Neodymium Iron Boron Earth Magnets
Size:D50*30mm D50*20mm D40*20mm
Operating temperature: Maximum80° C
Magnetizingdirection:N-S-poleinthe two largestsurface
NOT use to water meter ,gas meter ,electric meter ,it is harmful to your country . and i can not promise to stop any meter deviece.
Sometimes one of hundred will be like that surface and side maybe 1-2mm tolerance or Groove . we will be so sorry for it ,but it will be aslo strong ,and not affect to use . so please understand it .it is normal .