Flat Roof PV Mounting System features modular design.

Comprised of fully assembled ballast bay and module clip, Unirac RM requires just one tool for assembly. Each ballast bay is compact, weighing less than 3.5 lb.

[source: http://news.thomasnet.com/fullstory/Flat-Roof-PV-Mounting-System-features-modular-design-20011324]