This is the STOCK ROM of LG P705 only. This is flashable via KDZ Flasher. You can search google to download KDZ Flasher and also the driver for this phone.
Before flashing your phone make sure you have enough battery juice to flash your phone. Make sure it has atleast 50%. Also make sure that you have a good USB cable. When it stop in flashing it might brick your phone.
The file is SUN Cellular Variant.
You can download the file here
LG P705 -- > Download HERE
KDZ Flasher -- > Download HERE
Driver -- > Download HERE
NOTE: If the driver does not work, you can find the latest driver in the official LG website.