... good quality and price 3)has strong magnetic force Large Ring magnet N35,N38,N40,N42,N45,N48,N50,N52(M,H ... ,SH,UH,EH Largest size:OD170mm Ring shape with hole High coercive forceNeodymium Ring Magnet with N35,N38,N40,N42,N45,N48 ... .6, With precise tolerance.Application for NdFeB magnet:Magnetic separator, Sensors, Wind generators,Vibration motors,DC motors, Servo motors,Linear motors,VCM ...