There are two types: Manual Transfer Switch: Requires manual operation to shift load to backup power. Automatic Transfer Switch: Automatically shifts power to a generator during outages, preferred for convenience and seamless operation. In this guide, we'll break down the 12 main types of distribution boxes in a way that's easy to understand. We'll chat about what each one does, where it shines, and then dive into how to choose the perfect box for your needs. Main Distribution Board (MDB) 2. A distribution box comprises Engineering Thermoplastics such as Polycarbonate (PC), Acrylonitrile Styrene Acrylate (ASA), or epoxy-coated or powder-coated stainless steel.