Patent ID: 8274357

Claim:
A varistor comprising: a surge absorber sintered at a first predetermined temperature and having a first electrode and a second electrode; a first lead having a first end and a second end thereof, wherein the first end connected to the first electrode; a second lead having a first end and a second end thereof, wherein the first end connected to the second electrode; a coating enrobing the surge absorber and the first ends of the first lead and the second lead; and a ceramic case sintered at a second predetermined temperature higher than the first predetermined temperature, housing the surge absorber and the coating, having a first opening and a second opening, and made of Magnesium Oxide (MgO), Silicon dioxide (SiO 2 ) and 25 to 99 weight percent Aluminum Oxide (Al 2 O 3 ), wherein the second ends of the first lead and the second lead penetrate respectively the first opening and the second opening.