Protected: Scanner
It's used to scan the ghosts in Chapter 3 - 5.
All the In-game items you can find
Protected: Chainsaw
It's used to saw off The Watchers head in Chapter 1, and it can be used to saw off its offspring in Chapter 2.
Protected: E.M.P. Device
Is used to power electronics far and close. Can be used to Electrocute Anomalies. It can kill you instantly if you use it under water!
Protected: Walkie-Talkie
Is used to talk to people like the Scientist!