Lasersight
From Tomb Raider Wiki
The lasersight is an item in Tomb Raider: The Last Revelation and Tomb Raider: Chronicles. Lara has to use this to destroy certain objects with precision. The item can be combined with either the Revolver or the Crossbow.
Other than destroying items with it, it can be used to incapacitate the skeletons of The Last Revelation with a headshot. They will simply run around, helpless, if a headshot is done.
