Works great, but you have to adjust your wiring
Reviewed on 01/02/2018
These work great, but are quite confusing for the average home owner. Regular 3-way (and 4-way) switch wiring has two power wires going to/through every switch. (Ignoring grounds and neutral for simplicity, for two 3-way switches, a pair of wires goes between them. One at a time is "hot", the other is not. Flipping the switch at the "power" end changes which wire is "hot". Flipping the switch at the "output" (light) end, changes which wire the output is connected to. Any 4-way switches are added in the middle, and swap the two wires mid-stream.)
These GE Z-Wave/Bluetooth/WiFi switches are wired completely differently. Power is switched on/off ONLY in the main switch. The add-on switches need two wires (plus Ground) - neutral (shared with the rest of the electrical system), and a "traveler" (from add-on switch to the main switch). Any additional add-on switches are added in parallel to the first one. The "traveler" wire is only used for low-voltage signaling; it doesn't carry power. I'm uploading a diagram to make this more clear. Hopefully it will be visible from my review.
5 stars except for install headaches
Reviewed on 11/26/2016
The title does not tell you this, but the picture of the box, shows that this is the GE add-on switch, intended to be used with the 12727 GE Single Pole 3-Way Light Switches. These switches work in a pair to take care of situations where you have more than one location to switch on a light.
These are not trivial to install, even electricians I know have been left scratching their heads on this one. The first thing to know about them is that they do REQUIRE a neutral and an earth ground. I hear all you home electricians out there saying they all go back to the same place in the panel so it doesn't matter. I know it shouldn't, but it does. Trust me, I agree it should work, but it doesn't work right wired that way.
The second thing to understand, is that this is nothing more than a low power momentary contact switch that tells the primary switch to turn on or turn off. When wiring one of these in, one of the travelers from the primary circuit is connected to the traveler wire on this switch, and the neutral is connected to the neutral connector. This acts as a signal path. The other traveler, is connected to the load wire directly, bypassing the switch. So the end result is that you have a circuit created to send a signal back to the primary switch over the first traveler When the primary switch gets the signal from this add-on switch, it completes the 120V circuit over the second traveler turning on the light.
One other thing to note, these do not act as a z-wave repeater. The primary switch does, but the secondary switch doesn't have current to it all the time, so it doesn't include the z-ware repeater circuitry. I use the GE in-wall outlets around my house to spread the z-wave mesh around.
It took me about 3 days on and off to wrap my head around how these worked to wire them in right. Now it's a breeze to install them. Takes around 15 minutes and I'm done.
Other than the confusion that hopefully I have helped resolve for you above, these are great little switches. I use mine with a Wink hub and they do a great job of turning my lights on and off. In some places I have them turn on my lights, and I use the Oshram (spelling ?) lights so that I can dim them once they are on. I have an a couple of Amazon Dots spread around the house, linked with the Wink hub so I can turn on and off my lights either through automated schedules on or voice command. I've standardized on the GE line of switches for my wall switches and outlets and I'm very happy.