top quality material ndfeb magnet with hole used for many different fields produce as your request Hot-sale ndfeb countersink hole magnet Material:rare earth magnetSize:18*3 couple with 4mm countersink hole screwCoating:zinc/niTolerance:0.1mmApplication fields:speaker,toy ,motor,sensor and so on.FOB PRICE,not including shipping fee.FOR quantity of above 10,000 pcs