Laser getting shoter/longer

[Yimo]

Hi there
I've got a simple question on how to use the purple and light-blue entities of lasers
The ones that get shorter&larger in a specefic speed
Can someone screenshot an example on how to place the entities in the right order to make a similar laser ?
I couldn't find a map using this so I have to ask :/

[Ama]

screenshot_2014-07-09_00-47-39.png (200.02 KiB) Viewed 1249 times