Instruction: Answer the given question using the supporting document.

Input:
Question: Is it sensitive enough to detect a mild knock on a wooden front door?
Document: I have three of these on my doors and windows. They are sensitive enough to notice knocks and jolts to the door, but not so much that it constantly annoys you with false alarms. I have never had a problem with them so far; they are extremely reliable and offer peace of mind knowing when your door opens and the temperature of that area.I've used them for about six months now and, though I use them a lot (lot of door openings), I have yet to change the batteries.
Very good product works as expected, installed in my front door, just waiting a software update in order to be able to read the temperature in Celsius
The first unit I received was defective which happens sometimes. But customer service was great. They immediately sent me a new one which has been working perfectly for about a month. I have it on my front door and it does what it says it will do. Note that you may have to buy 3M double sided tape to get it mounted since the included tape isn't that strong. Also AAAA batteries are sold at Best Buy. You just have to look for them.
The temperature is an added benefit but as long as all the sensors are inside the house for obvious reasons, the temperature will vary very little.UPDATE: As per Ryan's (ST support) comment below, the 15ft is only required AT THE TIME OF INITIAL PAIRING. I have since verified that the max. distance is much more than 15ft, but... I never made it all the way to my front door, hence the 4 stars.
Zigbee devices all suffer from limited range, due to the higher frequency, and/or because more devices operate on this frequency (e.g. your phones or wifi) which cause interference.The leaflet in the box states specifically: "SmartSense Multi works best if it's within 15 feet (4.5m) of the SmartThings Hub when you connect it. I realized this too late and had to remove one sensor mounted on my front door, which turned out to be out of range.
(I got mine via the Kickstarter campaign)Pairs quickly and painlessly with a SmartThings hub. Does exactly what it says on the label; 5 stars.Note that this is a ZigBee (possibly ZigBee HA) device and will not work with Z-wave hubs.Right now I have it set up to monitor my front door - vibration (knocking) and contact (front door opened) - temperature is nice, but I haven't come up with a good way to use it.
- as a result, it's a bit smaller than similar devices. This made it a bit of a challenge to mount - the magnets are QUITE strong - but the passive (thin) side was thin enough to be mounted on both the bottom and one side. The contact closed range is around 5mm if you (like me) need a little air-gap.
I have had this system in operation for about 3 weeks. It includes 2 of these Multi-sensors; one on an interior door, the other on a door leading into a carport.
I have two of these sensors so far. One on my garage door and the other on a sliding door. The Smartthings Hub recognized the sensors immediately. These can sense open/close, temperature, and movement. I will be installing more when I get more into home automation.
On the interior door, I was able to mount the switch on the flat surface on the outside of the door. But for the exterior door, this was not feasible. * the double-back mounting tape included is VERY thin, and did not hold very well. Had to purchase 3M tape to get it to work.
Answer: I think it depends on how secure your door frame is, and how mild you're knocking... the sensor requires a decent vibration.  For example, I have one in my mailbox, and thunder will sometimes set it off.  Other times, a garbage truck would.  If your sensor is on the door (vs the frame), and(/or?) your door wiggles in the frame, then maybe...