Soil screw for Breezecatcher parallel drying racks

Need directions

We were confused with the purpose of the bright red plastic things and how they interface with the bolt. Called and spoke with Tom (who is incredibly nice) . There are no directions because it is very simple. I feel really dumb but still don't get it.

I'll know more when the weather warms up. It was some much more simple than having to dig a hole and pour concrete. I live in a rental unit so this was a perfect option.