Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: Does this work on the Physical Layer or Data Link layer? I have a device which uses ethernet to transmit video, the signal has to remain unchanged.
Document: I love these things, they work exactly as advertised and are fast! They come shipped without any documentation so you have to search the internet to figure out how to connect them.To save you all time, connect the black ethernet cable to your device or switch and the enclosed ethernet cable to the back of the Airwire and the black dongle. Plug the ac adapter in and repeat with the other side at your remote location.It just works.The LED lights should immediately come on (very obvious).
We have purchased and installed about 20 of these and frankly, they simply work flawlessly. They are an ethernet bridge and as such, they work at the ethernet level. This means that they do not require any ip configuration, they simply pass the signal from one antenna to the other.
This is truly plug and play, and it actually works.... no calls to tech support, no headaches, just plug it in and it works.We had a situation where I needed to have an ethernet device working in another building on my property. This product was recommended by my local computer store and this worked perfectly and reliably for what I needed. In fact, it worked so well that we bought two more units and set up a bridge for my oldest son's PS3.
I bout it for my invision , it's work great for streaming HD channels , no cables, no poor signal .i recommend this one to use it with media such as PlayStation or Xbox or receivers>
It does work but the advertisement said 100m (328ft) but I think it is clear line of sight. The distance I'm stuck with is 75ft but I have to go through 4 walls and 1 floor. I only get 1 LED for signal strength.Considering the signal strength I have with this I am impressed with the speed.
I had been needing something to allow me to do work from a room where there was not an ethernet outlet with a laptop that was not wireless enabled. This product filled the bill perfectly and worked right out of the box. I don't see any problems with the speed and so far it has been working reliably for about 2 months with no problems.
One less thing to troubleshoot!- single ethernet plug at each end, easy connection- power adapter plugs into an ethernet dongle, meaning you can place the antenna far from the power outlet simply by having a single long network cable between the connection point and the antennaAs far as signal distance goes, we have tested them in several environments and they work beautifully. They will work fine at a distance of 50-150 feet even in different rooms, one behind a counter, closed doors, different floors, etc.
I purchased this product because I have a 20m ethernet cable connecting my IPTV to my far modem. This product eliminated the need of this cable and I started enjoying watching the TV smoothly without any problem. I am planning to buy another one to connect the modem to a switch where I can connect multiple devices to it.
They have a sleek design and really look good.There are two negative points I can see. First, the ethernet/power dongle must be connected the correct way, otherwise the AirWire will not power up. It is well illustrated in the documentation, but it seems so easy that most people will just go ahead and connect it without looking at the docs, and end up with no power, scratching their head!
vary easy to use  , but the signal is not that high ,the best thing is : no need for configuration
Answer: To the best of my knowledge, the Air-Wire acts on the data-link layer.