423806 Quantity 1 piece(s) per pack Color Silver Material Ferrite magnet Specification Diameter: 20mm; Thickness: 1.5mm; This ferrite magnet ring is used for speaker， telephone receiver， microphone， alarm apparatus， stage speaker， car speaker; Electric products: permanent magnetic mechanism vacuum circuit breaker， magnetic latching relay， watt hour meter， water meter， acoustimeter， reed switch， sensor etc. Packing List 10 x Ferrite magnets