More information from the website:
Non-click
Our target users (stenographers) place an extreme emphasis on working with a quiet keyboard. After all, stenography often takes place right in the middle of free flowing conversation, such as in a courtroom or classroom, and the noise of rapid typing on a normal keyboard would be too distracting. Even the so-called “quiet click” keyboards are much too loud. Our key switch was specifically designed not to have any click mechanism.
Low Activation Force
Stenographers often find themselves typing for many continuous hours. Every extra effort to depress a key quickly adds up and can lead to serious injury. Our key switch has, as far as we can tell, the lowest actuation force (35cN) of any mechanical key switch on the market. This is 22% less force than required by the nearest comparable switch, the Cherry MX Red.
So a very light, linear and quiet Matias switch