VACTEC™ Perkins-Elmer®  LAMP/LDR         The Vactrol has a neon bulb on one side (2 pins close togheter) and a photocell on the other side  (2 pins that are far appart), As shown below. Manufacturer: VACTEC Perkins-Elmer Part Number: VTL9B8 Date Code: 7328 Voltage: Vactrol's input is 80Volts AC or 85Volts DC. Output Resistance: Lamp Off 15m Ohm Overall Size: .625" Tall x .620" Diam. Lead Length .26" Long Condition: New "NOS" New Old Stock w/Solder Dipped Leads Uses: Beseler lamp delay, Opto isolator circuits and Telephone ring detector