ALPS Switch
Alps switch is a old switch, began in 1983. Since, there are many redesigns and clones made by different companies, notably by Matias. [see Keyboard: Matias Mini Tactile Pro] ALPS switch was popularly used in Apple Extended Keyboard II, 1990 . For detail, see https://deskthority.net/wiki/Alps_SKCL/SKCM_series
![Alps switch 2021-01-08 WDKNr](ikm/Alps_switch_2021-01-08_WDKNr.jpg)
![Matias mechanical key switch](ikm/Matias_mechanical_key_switch.jpg)
The Matias mechanical key switch is used by Keyboardio model 1. See Keyboardio Model 1