EVERYTHING ABOUT SOLAR COMBINER HARNESS SUPPLIER

With Daisy Chain you get a daily wiring, though Leap Frog will save cash on wire and minimizes power losses made by warmth, being probably the most productive wiring approach. it is a dumb problem but I’m not solar panel savvy. What do the rubber plugs at the end of solar panels do? Are they important? I've 3 that are missing and I was informe