https://alexnld.com/product/us-plug-12v-5a-60w-ac-power-supply-unit-with-5-5mm-dc-plug-for-lcd-monitors-cord-output-tips-5-5x2-5mm/?hilite="US Plug 12V 2A / 4 Channel DVR AC Power Adapter, Output Tips: 5.5 x 2.5mm"