It is located at the storage of Carmel hospital:




It have a color changing LED indicator.
What is this device?

Looks like a WAP (Wireless Access Point). I must admit I like the label, I misread the CR AP bit at first sight  

Cisco is usually good kit, though. What is the power brick for..? The unit is obviously powered up so I'm guessing it's powered via PoE (Power over Ethernet) so not sure why a power supply is there.

Cisco prefers you use those power bricks with their WAPs.  Especially for long runs from the switch. 

Is WAP is similar to Router, but in a LAN instead of the internet?

Is WAP is similar to Router, but in a LAN instead of the internet?

WAP = Wireless Access Point - it is a device to allow wireless devices access to the network and/or the internet. Most routers have one built in, but if you have a wide area to cover, such as a hospital, you would need several of these at strategic points around the site.

Cisco prefers you use those power bricks with their WAPs.  Especially for long runs from the switch.  

That only works if you have power sockets where you need them. I had several (around 5 or 6 IIRC) Cisco Aironet WAP units around a site I worked at once. They were all powered over Ethernet simply because in the roof space of a large open warehouse-type structure, there were no power sockets.

In any case, I like equipment powered from sources I have control over. Plugging WAPs in locally means some idiot might switch them off. If they're wired back to the rack and powered from a UPS-backed switch or power injector, they're not likely to be switched off without me knowing about it..!

We plug in the bricks at the same location that the router and telco equipment is at.  At the power brick, 1 CAT-5 line goes to the router, the other line goes to the WAP.  We use these in my church buildings. 

We plug in the bricks at the same location that the router and telco equipment is at.  At the power brick, 1 CAT-5 line goes to the router, the other line goes to the WAP.  We use these in my church buildings.  

That's using power injectors and the WAP is fed power over the Ethernet link. That's fine, if you only have one or two devices. I meant using power bricks at the same location as the WAP and plugging it in directly. Firstly, it's not always possible as there isn't a power socket nearby, and secondly as I said, some idiot might switch it off.

I use a switch with PoE built in, that way I don't need a power injector for each device. At home, I only have a couple of IP phones, but when I was at work we had loads of devices all over the place so a separate power brick for each one would have been unmanageable.

By the way, Cat 5 is a bit out of date now, you might want to think about using Cat 6, or at the very least 5e.
 

Looks like there is an old telephone back plate on the wall..

I see these on the ceilings of stores sometimes. Plus sometimes with antennas.

We don't need anything right now that the 5e supports so they'll use the regular 5 cable that was installed years ago.