These parts are usually put together for customers as you need to switch the reducer round. If it is not assembled for whatever reason you just need to do the following:
- Undo the reducer screwed on the top of the bung.
- Screw the side entry tube onto the bung where the reducer came off.
- Put the reducer on top of the side entry tube ready for your lampholder.
The side entry tube is now the right way up so the flex can be gripped by the black cord grip above the entry hole in the tube.