02.Gas Discharge Tube (GDT) 2-electrode GDT SDH4-[ ] Y05-[ ] Y-[ ] Y08SV-[ ] U-[ ] Y20-[ ] Y49-[ ] 3-electrode GDT 3SDH4-[ ] 3Y06-[ ] 3YD-[ ] 3J-[ ] Surface Mount Types GDT SDH4-[ ] 3SDH4-[ ] High Voltage Types GDT Y08SV-[ ] Y-[ ] Coaxial Types GDT