The monitor-mounted IBM SurePoint 4820 Keypad was the first of the Model M "extended family" ("M-e") POS input devices, an undesignated extension of the Model M Retail POS keyboard family (Models M7 through M11) introduced by September 2000. This 32-key keypad was the smallest member of the "M-e" family typically mounted on the right side of various IBM SurePoint POS touchscreen monitors, and is considered to be a part of the pre-Modular (Pre-MPOS) series. In its default layout, 31 of the 32 keys are individually discrete, typically featuring a numeric keypad with a zero key taking up two key positions (hence 31) and a Ctrl key on the lower 4x4 key bank. Examples with or without an integrated magnetic stripe reader are known.