These drainage plates are important for many reasons:

The provide pasages for water that soaks through the soil to go down the slope of the roof.

They have little resevoirs that store water for the plants during dry spells.

They are made from 100% recycled post consumer waste plastic. 

In the south Bronx, we already handle  much of the city's recycleable waste, and so do communities like the South Bronx all over.  instead of letting the plastic leave our area, we want to grow green roof component manufacturing right here to provide more jobs and keep more money in our local economy.