Our products do not need to preheat ahead of time, namely hot type electric water heater does not need the tank of tank of inside store of big bulky body and heat preservation layer on the design so, most bulk is small, weight is light, and easy installation, save space, save material. Thus, the main advantage of the electric shower is that you heat only as much water as you use, as opposed to a conventional water heater, where power is wasted heating more water than is required. This makes the electrical water heater very economical.