... N40,N42,N45,N48,N50,N52 round magnets with holes, Any size Product specifications:1. neodymium rare earth round magnets with holes are with material grades of N35, ... N38,N40,N42,N45,N48,N50,N52(M,H,SH,UH ... ,EH) etc.2. Working temperature for neodymium round magnets with holes:from 80 centigrades ...