Product name : pot magnet Custom Super Strong permanent N50 Neodymium Arc Magnets for PM motor Shape:Segment, Disc, Cylinder/Rod, Ring, Countersunk, Segment, Trapezoid, Irregular shapes are available, Customized shapes for Sintered NdFeB Magnet are also available) Direction of magnetisation : Through the thickness or through the diameter Type of coating : Nickel, Ni-Cu-Ni, Zn, Gold, Silver, Copper, Epoxy, Chemical, PTFE, Parylene, Everlube, Passivation and so on. Grade : N35,N38,N40,N42,N45,N48,N50,N52 Tolerance in size : +/-0.1 mm