This led beads are mainly for mechanical keyboard DIY, you can use it for any MXmechanical keyboard which support adding led. Not only Cherry Gateron Kailh MX switches can use it, all MX switches keyboard which support LED can use it.

There are many colors for your options. Rainbow fast means flashing fast rainbow led, rainbow slow means flashing slowly rainbow led. Rainbow blink in auto.

The purple led bulb is dark color which is not so bright, if you care about it, pls not order it.

3mm is round, 2x3x4 is squre,1.8mm is the thinnest. If your keycap is very thick, you'd better choose 1.8mm led, if your keycap is under 1.5mm thickness, normal 3mm 2x3x4 should be ok.

How to add led for mechanical keyboard:

Drop the keycaps, get the screws out and get the PCB board of the keyboard. Then use electric soldering iron to add the led.