 Game elements include Thermal Discouragement Beams ( lasers ) , Excursion <unk> ( tractor beams ) , and Hard Light Bridges , all of which can be transmitted through portals . Aerial Faith Plates launch the player or objects through the air and sometimes into portals . The player must disable turrets or avoid their line of sight . The Weighted Storage Cube has been redesigned , and there are new types : <unk> Cubes , which have prismatic lenses that redirect laser beams , spherical <unk> Safety Cubes , an antique version of the Weighted Storage Cube used in the underground levels , and a cube @-@ turret hybrid created by Wheatley after taking control of Aperture . The heart @-@ decorated Weighted Companion Cube reappears briefly . Early demonstrations included Pneumatic Diversity Vents , shown to transport objects and transfer suction power through portals , but these do not appear in the final game . All of these game elements open locked doors , or help or hamper the character from reaching the exit . 
