Plus, since these are stronger, you wouldn't have to have them tilted on their side, you could just leave them flat. The magnet inside the iris sensor is REALLY small. So, it doesn't take much. But they are finicky on the alignment...but that's true with their own magnets as well.
I have both Iris v1 and v2 contact sensors and I prefer the v1’s. The v2’s don’t have a separate hardware magnetic switch like the v1’s. So I believe the v1’s are a tiny bit faster but the reason I prefer the v1’s is that I actually drill small holes in the case and solder a wire on to each side of the switch to make super cheap water sensors. I have at least 15 v1’s in use and 5 or 6 of the v2’s without any problems for almost a year that I’ve had Hubitat.
You can also solder other sensors to those like a Photo Light Sensitive Resistor on those v1 contacts. What does the ebay seller do with all of those magnets?
This is what I meant with "offset" - to shift the magnet over a bit so it would align and trigger the sensor repeatedly. Might look a bit fugly, but it works, and at the combined price is not a deal breaker.
Btw - this is my garage door MyQ "open/close" sensor. When the door opens/closes, the hinge part with the sensor (which is not screwed down into the support) will rotate - indicating status.
I would avoid the 1st gen DWS800, along with all 1st gen Iris stuff. If you don’t already have a bunch of it, no reason to buy non-standards-compliant devices.
I have had good luck with the 3320-L. I’ve never used the iL06-1.
I've had good luck with the iL06-1's, ended up buying 10 extras just to have on hand. Actually have all three, would agree about avoiding the Gen1 due to their lack of standards compliance. Had all of my V1 devices disappear at once, likely due to a V1 button that met its end at the hands of a strong EM field. From a "look-and-feel" perspective, I prefer the iL06-1's over the 3320-L's.
I wondered about magnet use and alignment for the v3s without magnets being in the same boat. This is a video for Iris v2 contact sensor installation but likely still useful for the v3s. https://youtu.be/9xV_JC39l3I
I had all of my first gen iris contacts and motion sensors fall of the network one morning...had to reset and repair them all. Replaced them all with V2’s soon as I could!
I was wondering about the other side of the sensor. the pics just make it look like it's one side. and not the other side which comes in contact with the other.
As @ogiewon indicated, the "other side" is a magnet. You can use any magnet. That particular ebay seller doesn't provide the magnet with the contact sensor.
As an aside, contact sensors work by having a magnetic switch, called a reed switch, on the inside. When sensor is close to a magnet (any magnet), the switch is attracted by the magnet to be in the closed position. When the sensor is removed from the proximity of the magnet, the switch reverts to being in the open position.