One Deco E4 t is powered by a standard 12V power adapter, although I highy recommend do not buy the E4. It has a major flaw and this is it's Ethernet 100Mbit/s ports. Just imagine, your ISP modem or router with 1Gbit contract, you will never be able to get more than 100Mbit with the E4. This is a big no go. I advise you to invest in the M4 system, it comes with similar sized devices and offers 1Gbit/s Ethernet ports. The price difference is very minimal for the M4 set.

TP-Link Deco M4 AC1200 Dualband WLAN Mesh 3-pack

The M4 also use the same 12 power adapters.