# What is this gadget by the door in my hotel room? **URL:** \ **Category:** Factual Questions\ **Created:** [September 13, 2014, 12:53am UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352 "2014-09-13T00:53:20Z")\ **Posts on this page:** 15\ **Page:** 2
**Author:** ![etv78](https://avatars.discourse-cdn.com/v4/letter/e/d78d45/32.png) [@etv78](https://boards.straightdope.com/u/etv78)\ **Post date:** [September 13, 2014, 9:16pm UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/21 "2014-09-13T21:16:37Z")
Sherrerd: Paranoid much?! My guess: CO detector ---
**Author:** ![kayT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayt/32/3633_2.png) [@kayT](https://boards.straightdope.com/u/kayT)\ **Post date:** [September 13, 2014, 9:20pm UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/22 "2014-09-13T21:20:07Z")
I hope someone comes back in here and tells us what that is! ---
**Author:** ![AncientHumanoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ancienthumanoid/32/278_2.png) [@AncientHumanoid](https://boards.straightdope.com/u/AncientHumanoid)\ **Post date:** [September 13, 2014, 9:30pm UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/23 "2014-09-13T21:30:35Z")
They live. ---
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [September 13, 2014, 9:36pm UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/24 "2014-09-13T21:36:51Z")
It’s the IR controller for that grid ball thing. ---
**Author:** ![CWN](https://avatars.discourse-cdn.com/v4/letter/c/bc79bd/32.png) [@CWN](https://boards.straightdope.com/u/CWN)\ **Post date:** [September 13, 2014, 10:57pm UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/25 "2014-09-13T22:57:13Z")
It is an infrared diffused mode wireless transmitter. It is a member of INNCOMs Integrated Room Automation System (IRAS). Most commonly, it is used as a wireless door switch transmitter to report door open and close status to the e4 digital thermostat. Here is a website for the item [**S541**](http://www.alibaba.com/product-detail/Wireless-Transmitter-S541_253493644.html) ---
**Author:** ![Sherrerd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sherrerd/32/8_2.png) [@Sherrerd](https://boards.straightdope.com/u/Sherrerd)\ **Post date:** [September 13, 2014, 11:20pm UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/26 "2014-09-13T23:20:22Z")
> [@etv78](#): > > Sherrerd: Paranoid much?! I was going for the laugh. (Of course the NSA _does_ get up to quite a lot, whether we laugh or not.) ---
**Author:** ![zoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zoid/32/336_2.png) [@zoid](https://boards.straightdope.com/u/zoid)\ **Post date:** [September 13, 2014, 11:29pm UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/27 "2014-09-13T23:29:36Z")
Looks like CWN got it. [Here’s a google image search](https://www.google.com/search?newwindow=1&biw=1600&bih=713&tbm=isch&sa=1&q=INNCOM+IRAS+S541+wireless+transmitter&oq=INNCOM+IRAS+S541+wireless+transmitter&gs_l=img.3...97724.97724.0.98250.1.1.0.0.0.0.77.77.1.1.0....0...1c.1.53.img..1.0.0.cYTCHMHsVLI): ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [September 13, 2014, 11:39pm UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/28 "2014-09-13T23:39:46Z")
> [@CWN](#): > > It is an infrared diffused mode wireless transmitter. It is a member of INNCOMs Integrated Room Automation System (IRAS). Most commonly, it is used as a wireless door switch transmitter to report door open and close status to the e4 digital thermostat. > Here is a website for the item [**S541**](http://www.alibaba.com/product-detail/Wireless-Transmitter-S541_253493644.html) That’s it! My faith in the 'Dope has been restored. I was beginning to worry, because it seems that whenever someone has a “What is this?” question the answer comes within five minutes, in quadruplicate. This one took a little longer. Next time I’m up there I’ll take out my phone and look for IR signals coming from it when I open the door. If I can see flashes, I’ll snap a picture and post it. ETA: Now that we know what it is, I see someone else was [asking about the mystery object on their blog](http://bobarno.com/thiefhunters/hotel-oddity-10/). ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [September 30, 2014, 11:59pm UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/29 "2014-09-30T23:59:06Z")
Well, here I am on my monthly trip to Connecticut. First thing I did after settling down was to inspect the S541 device. I put my iPhone in “selfie mode” and used the front camera to monitor the device as I opened the door. [Caught it in the act!](http://img.photobucket.com/albums/v186/minor7flat5/FD541931-0A68-440B-AA49-6D9C168CE9FF.jpg) A glance at the thermostat showed that the top left corner is black, obviously where a IR receiver is listening for those invisible door signals. ---
**Author:** ![Digital\_is\_the\_new\_Analog](https://avatars.discourse-cdn.com/v4/letter/d/a88e4f/32.png) [@Digital\_is\_the\_new\_Analog](https://boards.straightdope.com/u/Digital_is_the_new_Analog)\ **Post date:** [October 1, 2014, 1:38am UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/30 "2014-10-01T01:38:44Z")
Yay! Closure. 🙂 ---
**Author:** ![Shark](https://avatars.discourse-cdn.com/v4/letter/s/73ab20/32.png) [@Shark](https://boards.straightdope.com/u/Shark)\ **Post date:** [October 1, 2014, 5:37pm UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/31 "2014-10-01T17:37:32Z")
> [@Digital\_is\_the\_new\_Analog](#): > > Yay! Closure. 🙂 And upon opening too. ---
**Author:** ![Ranger\_Jeff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranger_jeff/32/2065_2.png) [@Ranger\_Jeff](https://boards.straightdope.com/u/Ranger_Jeff)\ **Post date:** [October 2, 2014, 4:33am UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/32 "2014-10-02T04:33:30Z")
So, that’s the “Official” story on what they’re used for. What do you think the NSA really uses them for? ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [October 2, 2014, 4:26pm UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/33 "2014-10-02T16:26:39Z")
> [@Ranger\_Jeff](#): > > So, that’s the “Official” story on what they’re used for. What do you think the NSA really uses them for? If the sensors are on a wireless circuit, I presume that, for real, the signals could be intercepted and an outline/heat profile of anyone/thing could be reconstructed. What are the infrared probe frequency/strength requirements for that? ---
**Author:** ![Digital\_is\_the\_new\_Analog](https://avatars.discourse-cdn.com/v4/letter/d/a88e4f/32.png) [@Digital\_is\_the\_new\_Analog](https://boards.straightdope.com/u/Digital_is_the_new_Analog)\ **Post date:** [October 3, 2014, 1:54am UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/34 "2014-10-03T01:54:12Z")
> [@Shark](#): > > And upon opening too. _groan_ Well done. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [October 3, 2014, 2:12am UTC](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352/35 "2014-10-03T02:12:09Z")
> [@Leo\_Bloom](#): > > If the sensors are on a wireless circuit, I presume that, for real, the signals could be intercepted and an outline/heat profile of anyone/thing could be reconstructed. > > What are the infrared probe frequency/strength requirements for that? Care to explain how this would work? [Previous page](https://boards.straightdope.com/t/what-is-this-gadget-by-the-door-in-my-hotel-room/698352.md?page=1)