When wiring the 3-Way Smart Dimmer Switch, model CWF500D-3W, it is important to note that the installation differs from a standard 3-way circuit. 

The 3-way Smart Dimmer controls all functions to the light fixture. The secondary switch (which should be a standard, non-dimmable, 3-way switch) simply provides on/off commands, which are sent to the Smart Dimmer via the traveler wire. 

All 5 wires need to be connected to the 3-way Smart Dimmer (Hot, Load, Neutral, Traveler, and Ground). What would be used as the second traveler wire will now be installed in the load position of the Smart Dimmer. 

This load wire (coming from the Smart Dimmer) will need to be spliced to the load wire in the secondary switch box, thus going directly to the light fixture. The load wire will not connect to the secondary switch. Not all homes are wired the same; if your setup differs we recommend contacting an electrician. 

On the secondary switch, connect the traveler wire in one of the switch's traveler terminals. 
The neutral wire should be connected in the common/load terminal and is used to provide power to the secondary switch (again, not all homes are the same). Make sure to insulate the second traveler position (on the secondary switch) as it will not be used. 

This wiring setup allows the secondary switch to receive power through the neutral wire; when the secondary switch is flipped, voltage is sent down the traveler wire to the Smart Dimmer, and the Smart Dimmer then performs the action accordingly. 

Please note not every home setup is the same. If you are unsure of the wiring configuration in your home, or you do not feel confident in your ability to wire the switch(es), we recommend contacting a licensed electrician to review and assist in the installation.