The package provides four primary commands for vertically scaling and stretching objects, and a number of derivative commands. Its primary function is the ability to scale/stretch and shift one object to conform to the vertical size of a specified second object. This feature can be useful in both equations and schematic diagrams. Additionally, the scaling and stretching commands offer constraints on maximum width and/or minimum aspect ratio, which are often used to preserve legibility or for the sake of general appearance. The package will, by default, preserve the current math style in the arguments to its macros. For the sake of compilation efficiency, however, this feature may be turned off and on at will by the user.