1.This link is only the shaft and switches for mechanical keyboard,no keyboard included.It's 3 pin switches
2.It can support SMD leds.
If you want to install 2 pin 4 pin switch leds, you need to solder led at first onto PCB and then put on switches on
3.TTC Gold pink is linear switches,actuation weight is around 37gf.Total travel distance is around 4mm
4.The lifetime is around 100 million times