The Palm m100 series consists of four Palm OS base personal digital assistants (or PDAs) titled m100, m105, m125, and m130. These models were intended to be "entry-level" PDAs. Their cases were built from cheaper materials, the covers of the LCD screens and the digitizers were plastic rather than glass, and the screens were smaller than the more expensive palms. Unlike other Palm computers, which had rechargeable batteries, they were designed to run on standard dry cell batteries (except for the m130, which uses a rechargeable battery). All feature a hinged screen cover with a small window over the screen through which the system clock can be viewed for a few seconds when the "scroll up" button is depressed through a hole in the cover, when the unit is not in use.