I believe their are two models of this device. The older one is a fast Ethernet and the newer is a gigabit Ethernet. The newer model will specify gigabit speeds on the label as well as have the Gigabit logo. This also shows up as a Class 4 device capable of delivering up to 30W of power which is much more than than will ever be drawn from the micro usb connector. I have had one of these powering a Raspberry Pi 3B+ at gigabit speeds with no issues! Nice for the price and Gigabit!

it worked as advertised. it works with Amazon Cloud Camera. ACC requires 5.2V. USB powered sources generally have 4.8 to 5.2V, and it's common to post maximum Voltage. This product delivers 5V, and it worked perfectly with ACC. I had IP camera ports on the ceilings, and was looking for ways to power ACC over ethernet; this worked without a hassle. It does requires POE capable level 2 switch which is the route I took. but from the instruction, there is another device called power injector where it can inject power to ethernet cable.
I haven't read up on the standard on the POE, but it appears that it does involves hand shaking between power source and consumer. There are connectors that looks similar to this product; however doesn't do handshaking; thus they are useless for my cases. This device provides the handshake and it always asks for 5V, so do make sure that's the amount of voltage, your device need.

I purchased a few of these for a new construction project to try to do whole home audio with Amazon Echo Dots. I was disappointed to find that while it would power most any other micro usb device I tried, it would not power the dot. I didn't have time to return the units (I bought 4-5) because I was too busy. I was very impressed that the seller reached out about my issue. They even sent a newer version (from China) for me to test. The newer version does work with the dot. While I would think POE should be POE and this should work with any micro usb device that needs 5 v 2.4amp, i'm really impressed that the seller is actively researching and improving the quality of their product when they get feedback. No product is perfect but this one is 5 stars in my mind.

CAUTION: DOES NOT WORK 'OUT OF THE BOX' WITH RASPBERRY PI 3B+ ... read for details

I have used around 12 of these generally excellent devices to power Raspberry Pi 2s and 3s. Having POE powered RPis is a life-saver when needing to do a remote reboot or to install in locations without power. I highly recommend this splitter for 2/3B RPis but NOT for the RPi3B+.

With the RPi 3B+ (which is the first with a pseudo-gigabit ethernet port), this splitter will NOT auto-negotiate a network connection (on fresh new Raspbian image with all updates). It powers the RPi with no problem, but the network connection is inactive/dead. After a little trial-and-error troubleshooting, I figured out that the link will not autonegotiate, but if set manually it will work but ONLY at 100mbit with HALF duplex (which is as fast as the POE splitter can do anyway since it is not a gigabit splitter). (Performance at full duplex was about 10% of that at half duplex.) (The RPi performed very well on a direct gigabit connection, so the splitter is definitely playing a role in the problem.)

To make it work on an Rpi3B+, do the following from an ssh shell (you have to temporarily use some other network/power connections to get it working):
sudo apt-get install ethtool
sudo ethtool -s eth0 speed 100 duplex half autoneg off

I also had to manually set my switch port to 100mbit half duplex because my switch (Unifi US-8-60W) would not autonegotiate.

I would recommend this for older Raspberry Pis, but NOT for the RPi 3B+ because it requires additional steps and wouldn't support the gigabit speeds even if it worked as designed (this is only a 100mbit device).

This device works great. I've purchased 4 of these overall and have had no issues with them to power raspberry pi 3 B's that I plugged into these. I'm ticking off 1 star due to the fact that they're 10/100 Mbps only. This won't matter for any pi except the new Raspberry Pi3B+ which happens to be what I'm upgrading my cluster to. The 3B+ now supports higher than 100 Mbps connection speeds, which means these adapters are going to be your choke point for bandwidth. The frustration of having to replace these units just because the manufacturer cheaped out and didn't want to populate all 4 ethernet pairs is what makes me take off the star. The product description only mentions this once and near the end of it's specs... so it's a little bit misleading.