This is a very cheap way to give yourself some POE ports if you need them, without swapping out your non-POE switch. I have no clue why people are complaining in their reviews that the power supply is big. Umm, do you want a cheap POS that will overload and die an early death, or one that will run reliably for the long term by not being run at its max capacity when all eight ports are loaded up? I choose the latter.

For the techies, keep in mind that this device is strictly standard 15.4w 802.3af power over ethernet, it will NOT power devices that require 802.3at 30 watt switch ports. So phones, access points, etc. will typically work fine, but higher end stuff may not. For example, I have a Cisco 1532i external access point that will power up the system board on 15.4w ports, but will not turn the radios on unless it's on a 30w port.

I'm currently running a Cisco IP phone with 7" screen, two Cisco 2702i access points and five Elan G! 10-inch touch panels for my home automation system off of this device with zero issues, so it has no problem keeping up with a full power load.

The vendor sells other versions if you want a "system" that includes power supply and the injector. This is just the injector, no power supply. This is for those who have custom power requirements. I recommend that you do not order this if you haven't read up on POE and don't understand how to use it.

I have found that almost all POE kits that include power supplies, whether passive injectors like this or POE network switches, do not provide enough power to fully populate all ports at full 802.3af at 15.4 watts per port, let alone 802.3at at 25.5 watts per port. This is fine for most systems where average power per port is less than maximum but if you have long-distance IR illuminators that take more power you'll find your cameras dropping out intermittently or even premature power supply failure.

To fully power 8 ports of 802.3at you need a 204 watt power supply; 8 ports of 802.3af requires 124 watts. If you look at 8-port POE injectors or switches, almost none have power supplies that can fully support the standard. This is a topic for which Wikipedia is your friend. There's a great article there. For 48v, figure just at a half amp of power supply current per 802.3at port at full power, or 4 amps for one of these injectors. To prevent premature failure, I recommend using a power supply rated for 1 amp per port, or 8 amps for this injector, so that you're operating at 50% capacity over time, extending the life of the power supply.

If you need more power than the kits have, then this no-power-supply version is great. Why buy a kit with a power supply that won't work for you? If you don't need full power then why include more-expensive power supplies in the kits? The seller of this item has plenty of kits that offer a great balance of power versus cost for most people. No, I don't have any affiliation with them. Other than them responding to a technical question I posted here on Amazon once, I've never had any contact with them. But when your needs are outside of the 80%, I'm thankful to them for selling this injector that I can customize myself.

I purchased a 48v power supply from Amazon: Genssi 48V DC 7.3A 350W Regulated Switching Power Supply and mounted it in a metal box I purchased elsewhere (the only suitably-sized, inexpensive, box I could find was a box made for a DSC 1832 alarm panel; just search). The power supply I ordered did not come with mounting brackets. I can't find the link where I ordered the brackets for a lot less than this link but here's a link where you can order the mounting brackets to fit Mean Well power supplies: Mounting Brackets for Mean Well Power Supplies . For better prices - much better prices - on the brackets, search for MHS014 and look for Mean Well (or Meanwell) in the results. Put this all together and you have a super reliable POE system that can fully power all ports.

I'm using this WS-POE-8 to power my Q-See HD 1080P cameras. I think the cameras are QCN8012B and are 12v. First of all the unit is small and very light, maybe 8" long, 1"1/2" wide, and 3/4" thick? It's not very big and feels a little flimsy as it's all plastic. The Power block is your typical size almost like what you get with a laptop. When it's on, there is a small green led that comes on to show that it has power. The unit is black plastic and has 8 ports in and out. Very simple to plug in your items. Like my HD cameras, they go on the port that says POE which injects power on that side to power that device. The Lan side plugs into your router or wireless bridge. Great way to add IP cameras on the other side of the house that might be too far using the 100ft ethernet cable. So far it's working great. Will post if my power supply goes out as I've read some have, but this one is great so far. Oh i'm using the linksys wireless bridge WUMC710 to hook into my netgear X6 router which connects to my NVR.

Turns out this is does exactly what I need... simple, easy, works well to inject Passive POE into multiple lines at once (24v in my case). Only giving 4 stars since I was disappointed to find that the case is made of plastic. It's textured to look like painted metal, but it's definitely plastic. Using this in a high RF environment, I would have strongly preferred a metal case for shielding, as well as for long term robustness.

Update 6/19/17
I've used this product for a while now and it's a real workhorse. Does everything a PoE injector should do and nothing it shouldn't and at the right price to boot. Couldn't recommend it any higher.

**Update**
I was curious what the red barrel adapter actually does (the image indicates it's for a legacy cisco VOIP phone) so I used a multimeter to confirm that all it does is swap the polarity of the power. When in use, the LED on the unit itself turns red instead of green. This adapter has no impact on resistance or voltage - only polarity.

This is a great adapter at a great price, and something people seem to often forget is that it can be difficult to mix POE/non-POE products, because sending POE to something not designed to handle POE will nearly certainly destroy it. This allows for easy mixing of POE devices with a normal switch without worrying about accidentally destroying any equipment because its sending voltage the receiving device wasn't prepared for.

Having said that, it is important that you realize that this is not a switch and it requires an external switch. It will require an ethernet cord from the switch to the POE adapter, then an additional ethernet cord to your POE device - this is for each and every POE device.

Finally, I would like to mention that no consumer grade IP camera feeds a stream that is anywhere near 100mbps, and if it did, you probably wouldn't be able to properly capture it anyway - so there is literally no advantage to having gigabit over 100mbit when it comes to IP cameras.