A Molecular Compressor is a handheld device that can alter the size of a creature or object. In "The Future Is Underground", Luis shrinks Emily, C.G. and Ethan so they can search a terabyte mound for water. Once they became trapped, they had to exit quickly, or run the risks of being crushed to death when the effects wears off. Then in "He Might Be Giant", Ethan was turned into a giant, to remove a fallen tree off the Time Flyer. (Much of the drama that ensued could have been avoided, if they shrank the tree and regrew it elsewhere, in the first place.) The effects wear off in about an hour.