Spark Plug Cap - NGK LB05E Resistor
NGK LB05E 90 Degree Resistor Spark Plug Cap
5k ohm resistance Plug Cap for models with Electronic Ignition
Can be used on any Classic Vespa or Lambretta
E is for terminal nut
F is Terminal stud.
Either NGK LB05-E or LB05-F will work. You will have to remove the screwed on tip (terminal ferrule) on the plug with the "F" Cap
LB05E caps fit conventional spark plugs with terminal ferrule like the NGK B*HS / B*ES