This is map 3 of 4 in PFT: Classic, which is the original version of the mod before the recent overhaul.
More information here: Moddb.com
To install and play:
- Extract the zip to your portal 2 maps folder usually located at C:\programfiles\Steam\Steamapps\common\Portal 2\portal2\maps
- Start Portal 2
- In the developer console (Options -> Keyboard/Mouse -> Allow Developer Console, then press the ~ key), type the following command: