I just bought a C-8 and trying to find compatible contact sensors (doors/windows).
I've heard the Tuya ones work well on AliEx (1005006215113198) but the eWeLink (1005007333970530) one has better specs claiming 5mm distance detection vs 15mm.
I've searched the forums and the documentation but couldn't find either (could be that I'm not looking for the right thing.
I'm also hearing SONOFF is a reliable option but it's $10 more per. Hoping for some practical guidance here. Thanks.
I've used lots of Aqara contact sensors and they are good.
It's hard to go wrong with IKEA.
Their ZigBee line and Symfonisk speakers are very good value, especially when they're running a $50 off $200 sale with free shipping. 
They seem quite a bit larger than the Aqara with the rechargable AAA . Worth a look if they last over a year?
No experience with them I just wonder about the AAA self-draining over a long period of time.
Not sure what this spec is, but are they just saying one has a stronger magnet than the other? 
Mine is only about 6 months old and very seldom triggered but battery level hasn't changed.
The good news is that IKEA has a 365 day return policy if you decide it's the wrong fit.
@Ranchitat I thought this meant the door can open 15mm without detection vs 5mm. Which both seem a bit ridiculously high. Surely the sensors can detect changes with less than that. Hell I remember programming debounce in assembly for buttons 
I think they're just referencing the max distance on your door to frame gap.
@Ranchitat yup, that's definitely what it is now that I'm thinking that through again – oh boy, don't judge me
Hubitats compatible device list is below. For those of us who want the certainty of tested devices.
These are awesome. Batteries last about a year. Also have temp built in. At $4.50 each the price can't be beat.
The gap means the max distance between the sensor and the magnet that came with the sensor before the sensor registers open.
Depending upon your use case and the install geometry, a larger gap is often preferable, because that gives more leeway for the sensor to register closed.
Today I installed a sensor on a sliding glass door to track when the latch is in the locked position. In this install, I specifically sought a sensor with a 1/4" range due to geometrical constraints.
Can confirm. I have a few of these also.
Download the Hubitat app
