@Tecboy 

You may be able to keep Netgear range extender, why replace it if it works for you? What that range extender is connected to (WiFi router?), and do you plan to keep that WiFi router after you've added Deco XE75?

Also, does Ring camera support 5GHz or is it 2.4GHz only?

  @Alexandre. 

The Netgear extender(dedicated to one Ring camera on a different SSID) is failing...drops connection every few days...I have another larger netgear triband extender which is on its last leg. This extender will be replaced with  the second XE75 unit and the main XE75 unit will be near my existing ISP wifi router (Zyzel)

Eventually i plan on eliminating my ISP wifi router(required for cable boxes to connect) and replace with new mesh system. When i get the XE75...i plan on setting up in AP mode for a short period of time...then change to router mode once my ISP Wifi router is removed

All 3 Ring cameras support both 2.4 and 5Ghz

  @Tecboy 

If you plan to replace your Netgear range extender, I can't tell which other range extender will work with Deco mesh. Most should, but it would be a good idea to get extender from the place with easy return policy, in case it won't. 

I can only give general recommendations. First, try connecting Ring camera to your new XE75 Deco mesh. It may work. To make camera connect to the nearest Deco unit, force it to use 5GHz only. 

If that doesn't work, and if your garage is not insulated and in hot/cold climate, you should be looking for outdoor range extender. This will limit your options, and simplify the selection process.

Either that, or get Deco X50 Outdoor for garage. 

  @Alexandre. 

the driveway cam needs to send signal thru double brick (old 1960s) wall. I purposely put a plug in wifi extender(netgear EX7500) in the garage(somewhat climate contolled) and on its own SSID so the driveway cam will always connect to it since its the closest (only 10 feet away). Where my main isp router and other netgear extender (EX8000) are located are too far away and too much of an angle to get any usable wifi signal. The Deco EX75 units will go at same locations as my isp router and larger netgear extender. I want to replace the failing netgear extender in my garage with another extender so i can specify different SSID for the RIng camera so it always connects to this specific extender. I was looking for a decent  plug in based TP-Link Extender that will compliment and work well with the 2 unit Deco EX75.

  @Tecboy 

I understand what you are trying to do. I would have left that type of configuration as a last resort, but it is me. 

For what you want to achieve, any decent range extender can do. You shouldn't constrain yourself with just TP-Link brand, it won't bring you any benefits. Range extenders and WiFi mesh are not supposed to complement each other, so I doubt TP-Link went extra mile to make sure their range extenders work better with their mesh than extender from other brand.

I have quite old Linksys RE4100w N600 range extender that I successfully connected to my TP-Link Deco mesh, as a test. 

Here is my recommendation: get XE75 and see if you can connect your Netgear range extender to Deco mesh. If you can, same should work for any other extender of your liking. Just make sure it can broadcast on separately configured SSID, as some just rebroadcast with SSID of WiFi router they are connected to.

Hint: some range extenders might not like dual band and prefer to connect to separate 5GHz and 2.4GHz bands on separate SSIDs. If this is the case, have Deco Main network broadcast 5GHz only, enable Guest network with 2.4GHz only and that will address this issue. If you have to do that, with Deco mesh in Access Point mode also configure Guest network to "Allow Local Access."