Chalk Line To mark straight traces on the roof to align mounting rails and various components. Wire Strippers/Cutters are utilised to prepare electrical wires by removing insulation and cutting them to the proper size. They're necessary to make Harmless and secure connections. Do it yourself setups normally absence that safety https://www.americanarraysolar.com/how-installing-a-heat-pump-in-fresno-saved-money-and-energy/