Editing Cherry M9 (section)

==Description==
In their 1982 catalogue, Cherry listed three different sizes of keyswitch: [[Cherry M7]] ("Standard Mounting Height"), [[Cherry M8]] ("Super Low Profile") and Cherry M9 ("[[low-profile|Low Profile]]"). Cherry M9 switches are designed to sit almost entirely below the plate, with a 9.14 mm distance from the top of the plate to the top of the PCB (down from 17.4 mm in the Cherry M7). From the diagram, this gives a total switch height of 12 mm. This corresponds closely with the 11.6 mm overall height of the [[Cherry MX]] switch, but with a requirement of a taller PCB−plate gap. Less than 3 mm of the switch is above the plate.

The MX shell design, including its retention clips and four top release holes, is quite similar to the M9's. However, the M9 is usually mounted with latches on top and bottom, rather than the sides, as with the MX.

The contact mechanism is the same as the [[Cherry M8]], with a lateral movable leaf.<ref name="Parak" />

The switch shell and slider can accommodate separate contact mechanisms for two circuits. In most cases, M9 switches are [[Cherry MX mount]] (seemingly a misnomer if M8 and M9 had this mount first).

Cherry M9 switches are fairly uncommon and appear to be more likely to be found in typewriters than computer or terminal keyboards. According to dates on shipping boxes, it was produced until at least 1985.

US patent 4339643 filed in 1980 describes a tactile double-action version and claims that this switch has hysteresis; no explanation for the hysteresis is immediately obvious and the term only appears once in the text of the patent.