You have a Pentair FNS Plus DE Filter and a Pentair Whisperflo Pump.
Click Here to View Pentair FNS Plus Parts
Click Here to View Pentair Whisperflo Pump Parts
You can run the system on backwash in order to drain the pool. You’ll need to close the skimmer and open up the main drain. However, I would recommend using a sump pump. It gets the job done quicker in my experience.