Edgeless Safety Cube Receptacle

The Edgeless Safety Cube Receptacle is a game mechanic used within Portal 2's co-op campaign. It is used within test chambers to activate a variety of effects. It activates only when an Edgeless Safety Cube is placed into it.

Trivia
GlaDOS states that humans have trouble placing an Edgless Safety Cube into a receptacle specifically designed for it.