Aiphone power supplies always work the first time you plug them in. Aiphone products may look cheap, but they always work. A cheaper Brand X power supply could have been used, but with the Aipohone UL listed power supply, I know that I will never have to go back to service this intercom system because of a faulty power supply. This system was installed in a preschool where safety comes first. The PS-1225UL can be wall-mounted and does not produce excessive heat.