The present disclosure relates to a mounting base for a crossarm and the crossarm. The mounting base may include a front-facing fastening surface, a rear-facing surface, and an opening formed between the front-facing fastening surface and the rear-facing surface, where the opening comprises a generally reverse L-Shaped geometry that extends through an entire width of the mounting base. The crossarm may include a first section and a second section that are oriented perpendicularly to each other, where the first section and second section are composed of composite material that contains a plurality of fibers within the composite material.