The Neo is standalone, no pigtail or place to add one. It looks like this one on the driver thread that @kkossev created:
Question about the Neo...how do you open it to look inside? I don't see an obvious way to open it up, or to start the pairing process. Is the orange strip supposed to be removed?
Yes, that's what I have for two of them...example below:
But how do you open the puck to press the reset button inside, and change the battery? Don't want to force it and don't see an obvious way to open the puck up.
Turn the top and bottom in opposite directions (counter clockwise)
OK, thanks. Tried that and it didn't open as easily as I expected and didn't want to force it. I'll go give it more muscle (such as I have). 
Thanks.
Worked! 
Big reset button in the lower right corner.
Yeah, had it installed, results below:
To get it in pairing mode seemed like I had to hold the reset button for 5s or so after the puck booted up (made loud beeping during startup).
I test by dipping sensor in cup of water
I'm afraid to test it - the alarm beep is pretty darn loud!
not that loud lol, turns off quickly
Still waiting for mine to arrive! Tracking tells me 6 days…
I ordered another type from AliExpress and it arrived before the one from Walmart!!!
Works! Detected wet when I put the sensor in some water.
For now have the sensor sitting on the salt, and the puck on the top of the tub inside. Will drill a hole so I can mount the sensor on the outside of the salt bin so I can get auditory warnings if I'm nearby.
Hope you get everything you ordered from Walmart.
AliExpress is surprisingly fast sometimes. (Or Walmart is surprisingly slow.) 
Next I need to look into splicing in some additional wire on the cable so I can place the sensor in my steam shower steam generator's holder, and have enough wire to place the puck near the attic entrance, so I don't have to hike all the way to where the generator is every time I have to replace the leak sensor batteries.
Yea, first order from Walmart… They have a lot of catching up to do to reach the Amazon level!!! Will continue to avoid their online service as much as possible…
A stereo mini extension may work...
https://www.amazon.com/Tripp-Lite-Extension-Headphones-P311-010/dp/B0091F8EZ8?th=1
Ooooo...interesting, I have some of those around I can try!! THanks.
Works!
I don't know if I'll run into an issue w/the length of the cable (impedance or resistance?) if the cable is very long, but w/an added about 2' of cable it worked as well as w/just the original cable only.
These look just like the Dome Zwave water sensor, except Zigbee. Like @danabw I added a headphone extension cable to my probe so it would reach into my sump pit - didn’t run into any issues. The probe ended up failing (even without the extension) and I got a warranty replacement from dome but then it failed again. My point is make sure you test often because I don’t trust that round probe.
Yeah I don't normally use one myself except for my softner. I test a random sensor about once a month. I also got them because they looked like my dome except zigbee 
I think as long as it gets continuity it should be fine.
Download the Hubitat app
