I got a BBQ Guru CyberQ WiFi for Christmas.
The manufacturer recommends installing the adapter through a vent hole. I decided to mount the adapter in a separate hole. I can then use the ATC on either of my WSMs. If I choose not to use the ATC, I can just leave the kill plug in the adapter and all the stock vents are fully functional.
I bought an extra WSM adapter and kill plug when I ordered my CyberQ WiFi.
WSM vent holes are 3/4", the WSM adapter is 1 1/4" ID. I have a 7/8" hole saw, and decided to use it. 7/8" is also a good choice because it is 1/2" trade size for electrical fittings. If I ever want to blank up the hole, a 1/2" electrical knockout (KO) seal will cover it right up.
I put blue tape over the hole drilling area and marked it out. I drilled a 1/4" pilot hole, then used my 7/8" hole saw. I did my 18 1/2" WSM first, then the 22 1/2".
7/8" hole drilled half way between the left leg and vent (it will be directly below my probe grommet).
Adapter installed (outside).
Adapter installed (inside).
Adapter side view.
Kill plug installed.
18 1/2" inside grate view.
22 1/2" side view.
Both WSMs, also showing the probe grommet directly above, and the thermometer mod.