A:Answer The PD-6WCL can be installed at any of the three locations for this 4-way lighting circuit. For ease of install, Lutron recommend installing the PD-6WCL at one of the 3-way locations. The remaining two locations will need to be replaced with Pico remotes, as well. If the mechanical switches are left in place, the PD-6WCL will not have a constant connection to power and load, therefore affecting how it operates.