Specification:

Size: Ring 19.4-5.25x12.6-45H Ni
Outer Dia: 19.4 mm
Inner Dia: 5.25 mm
Thickness: 12.6 mm 
Grade: 45H Ni
Coating: Nickle - Ni

Description:
Nickel Coated Magnets have many industrial, educational and household uses. These Magnets are highly resistant against demagnetization.