Details 1.This link is only Gateron Optical switches for optical switches keyboard. 2.It can support SMD optical keyboard,such as SK61 /SK64 /X-bow Nature Knight ?3.This optical switches can't interchange for mechanical MX switches.Such as GK61 GK64 can't use it.The bottom is different structure. Gateron Optical switches Optical Blue --Tactile clicky feeling,acuation weight is around 55±15gf,actuation distance is around 2.3mm Optical Black--Linear switches,actuation weight is around 60±15gf Optical Red--Linear switches,actuation weight is around 45±15gf Optical Brown--Tactile unclicky feeling,acuation weight is around 55±15gf Optical Silver--Linear switches,speed is faster than red,acuation weight is around 45±15gf Optical Yellow--Linear switches,acuation weight is around 35±15gfOptical green -- Linear switches,actuation 35±15gf.Total travel is around 4mmSilent Black Brown Red Yellow Silver is similar to normal black brown red yellow silver,just add a bump inside to reduce noise