The connection between different parts of electricity transmission happens through substations. These substations are smaller than power plants in in terms of scale. However, they are equally important. Substations also control and perform to adapt the voltage to each electrical delivery step. There two main voltage adjustment that a substation performs: from high to medium and from medium to low. A governmental body or a private entity like an electrical industry might own substations. The substation is a way of controlling electricity flow and measuring the voltage required for each stage. The first stage is the shift from the power plant generator to transmission bulks. There we found a first substation, and then we find a second one during the shift from transmission to distribution. Transformers of voltage are the main component of a substation. The objective is lowering down the voltage from high to medium then from medium to low. Knowing the importance of substations, e-electricity is providing a long list of electrical substations products.