Maybe the question will be answered on the manufacturer's site (?) Good luck. Our "Deco E4 Mesh 3er Set" is running great - indeed surprising for the price...

The S4 / M4 Deco have 2 Gigabit Ethernet connections, the E4 only have 100 Megabit connections, so an E4 set is cheaper. Tip: If the Internet provider offers a faster subscription than 100 megabit, Deco units can also be mixed, e.g. an S4 / M4 can be connected to a router or modem and a cheaper E4 used to expand the WLAN.

https://www.tp-link.com/de...