CV189
Protective spark gap
CV233
Surge arrestor
CV295
Spark gap
CV326
Lightning arrestor
CV402
Protective spark gap
CV488
Spark gap
CV980
Protective gap
CV986
Lightning arrester
CV1743
Protective spark gap
CV1858
Spark gap (unknown)
CV1859
Spark gap (unknown)
CV2248
Protective spark gap
CV2252
Protective spark gap