A floor grill
A Floor Grill is a building component able to be placed in floor frames. Floor Grills are able to be seen, but not shot, through. They are useful for allowing players to see if others are in a room or in front of the entrance to their base. Floor Grills offer less health, and invariably protection, than sheet metal (or arguably stone) floors. It is recommended to upgrade the floor frame in which the Floor Grill is placed to at least stone so that it will not prove to be a liability for the base.