We'll use this 2-lane Electonic Finish Line as an example. Larger Finish Lines are pretty much the same but may not use four washers per piece of track.

When you slide your Finish Line onto the track, you will probably want the green light towards the start gate. This way the person operating the start gate knows when it is ready.

Notice the two small openings that have been cut so that the Finish Line sensors have line of sight with each other. For each lane, there will be a sensor in the base as well as it's counterpart located under the crossbeam.

When you insert the batteries, the red lights will go through a test cycle. Make sure that the track isn't blocking the sensors. When the test cycle is finished, the green light will come on.

In the start gate, there will be holes drilled. When you receive your start gate, you will need to drill holes in your plank, board, ramp, or whatever structure that you are going to build to give your track the accelerator ramp.

In this 2-laner, you can see a bolt in the hole closest to you. This one can be fastened tightly.

Do not screw this bolt tightly! It is merely used to hold up the track, not to fasten it down.

Notice how the track is bowing inward around the bolt! It's too tight!

The operation of the start gate is simple.

The thumb uses the crossbeam for leverage while the fingers are draped over the top edge of the plexiglass.

With a little squeeze, the gate opens.

Each car will start at the same time and taller cars don't have to worry about hitting their top edge. Your hand will hold the plexiglass flat.