Difference between GE 12723 Add-On Switch and GE 45610WB Z-Wave Add On Auxiliary Switch

I have a three way setup, one dimmer and one switch now (can’t dim from the second switch). I want to replace it with a zwave switch so I’m getting the 12724 dimmer but what addon switch do I need. The 12723 is much cheaper so I’m confused on what’s better in the GE 45610WB.

12724: http://smile.amazon.com/GE-Z-Wave-Dimmer-In-Wall-12724/dp/B006LQFHN2/ref=pd_sim_60_6?ie=UTF8&dpID=41oHVPZwDbL&dpSrc=sims&preST=AC_UL160_SR83%2C160&refRID=01PAGVAG2HBN1ERKNZAT
12723: http://smile.amazon.com/GE-Z-Wave-Dimmer-In-Wall-12724/dp/B006LQFHN2/ref=pd_sim_60_6?ie=UTF8&dpID=41oHVPZwDbL&dpSrc=sims&preST=AC_UL160_SR83%2C160&refRID=01PAGVAG2HBN1ERKNZAT
45610WB: http://smile.amazon.com/45610WB-Z-Wave-Add-Auxiliary-Switch/dp/B0080G4OJO?sa-no-redirect=1

So this was a standard 3-4 way switch? If this is the case you need one dimmer switch and an addon switch for each location. I have a dimmer at one end of the downstairs hallway and the addon switch wired as a 3way. I can dim from either switch.

The add on switch is $18 from Smartthings store.

So what’s the other switch for? 45610WB That’s the switch they recommend for “addon”

You want the 12723. That other switch just looks like it’s overpriced from another seller.

According to this site: http://store.homeseer.com/store/Jasco-45610WB-Z-Wave-Add-On-Auxiliary-Switch-P1279.aspx

It is the older model of the 12723.

Regarding the 45610: “This auxiliary switch is a component of the GE Z-Wave® lighting control system and is designed to work with the 45607 Dimmer (ZW3002), 45612 Dimmer (ZW3003) and 45609 On/Off Relay Switch (ZW4001).”

I have a 45612 on a circuit with no neutral wire. How can I add a 12723–it looks like it needs a neutral? Is there a different way to connect it?