This is a heavy, transformer based inverter made for off grid and on grid both.  This makes it a hybrid inverter.  The Schneider XW PRO 6848 is battery based for any nominal 48V battery including lithium Iron Phosphate (LiFePO4).  

PDP stands for Power Distribution Panel.  Schneider makes two models of the PDP for the XW PRO inverter.  There is a small, and large PDP.  Both come with one 250A circuit breaker as a battery disconnect, and some AC circuit breakers.  Both have a means to connect the single 250A breaker to one inverter.

The small PDP is made for one inverter only.  It takes up less room, and costs a little less than the full size.  As of this video, it is about $650 which makes it a real bargain if you know for certain you only need one inverter.  This mounts under the inverter.

The large PDP takes up a little more room than the small PDP.  It mounts next to the inverter, and comes with a wire-way that mounts under the inverter.  The large PDP can accommodate up to 3 inverters allowing you to expand your system over time.  As of this video, it costs about $1,200.  It's only worth it if you know you will want more than one inverter (now or in the future).