 | “I can't get over how small you are!” This article is a stub. As such, it is not complete. You can help Portal wiki by expanding it. |
A Circuit Breaker helps to open doors in co-op mode, when pressed simultaneously with another Circuit Breaker located on the other side of a door. The Ping Tool's countdown function is useful for synchronizing the action with your partner. Also, it is used in the beginning of Chapter 6, The Fall
