Portal 2 Chapter 8 Test Chamber 4
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Chapter 8 - Test Chamber 4
sp_a4_tb_polarity.bsp 
This is the fifty-second level of the game, and takes place within an incomplete Aperture Science Test Chamber. This level features the Excursion Funnel, and introduces the way in which Buttons can be used to change the direction of Funnels. Turrets are present as an additional hazard in this level.
Threats faced
- Turrets
- Falling to your death
