Neodymium Ring Magnet  with north and south poles on opposing circular faces are used in many everyday appliances such as vacuum cleaners plus motors, generators, rotor shafts, speakers and more. Popular Size for Large Tweeter Speaker : Grade Size 35H D115*d70*6mm 40H D120*d60*10mm 38H D145*d85* 38H Axial  Nickel-plated (Ni-Cu-Ni) 35SH +/-0.05mm 35SH approx. 6.5kg 35H Axial