@Hisham_A yes, any unit connect at any unit in range but for best performace with wifi backhaul use any software for meansure SNR signal between units, if you get plus 24db of SNR wifi backhaul works fine. Less than 24db you get some trouble. 

@Hisham_A 

@leogz  , @kevin 

thank you bothe for your quik respond and helpfull information, win i receve the extra Deco and install it ill let you now how its go.

Regards

@Janingo No, you can't read at Deco App, but have some app to do this. 

Windows/Mac: https://www.netspotapp.com/

Mac: https://www.adriangranados.com/ (Wifi Explorer) 

Wifi Explorer o Mac, but rememer read SNR from place where spot are allocated not from your desk. Anything above 24db SNR you got full performance.

@Hisham_A 

Hi Dear 

i receved the Deco and i coneect all my howm, it working very good but i loss a lot of speed in the slave Deco the SNR betwin the Deco mor than 38db but i get less than quarter of my orginal speed, my ISP speed is 500 Mbbs and from the main Router wifi i get  500 and from the main Deco i get 380 if i vry closs i get more than 380 but win i in sacound flowr neer the slave Deco i get from 90 to 110 only all the slave deco are the same.

other quastion can i connect slave Deco to the Router that main deco connected to and get more speed? as you now the Deco have only 2 Ethernet LAN and i have 6 Decos.

thanks 

@Hisham_A  also i cant update my Deco to 1.4.1 i have 1.3.2 build 20190624, it give me system is currently up to date?

@Hisham_A You can use powerline to avoid WifiBackhaul down speed. Or ethernet from main deco. 8 ports switch linked to main deco and all others deco's. 

i have 300mpbs fiber here and got 300mbps in all decos via wifi backhaul but all with 35db plus SNR. Try location with 35db SNR to increase speed. 24db is a minimum. 

my topology  Main Deco ether to custom_4 , all other wifi Backhaul. 

With 6 points try 2 or 3 with ether backhaul to gain speed.