An introduction to Kailh switches, including Speed & Box – The Keyboard Company
Kailh Speed Copper SMD Switches Plate Mount Tactile-
Kailh seems to have a lineup of Super Speed switches (Bronze, Silver, Copper, Box Red) on AliExpress. Compared to the Speed series, they have a longer spring and are factory lubricated :
Amazon.com: Kailh Copper Mechanical Keyboard Switches - 120 Pack - Speed Tactile, 40g Actuation Force, Fast Response, for Gaming & Typing : Video Games