RGB Rainbow Backlight: RK gaming keyboard supports 18 RGB backlight modes, 8 monochrome backlight modes and 1 full-color backlight. The lighting can be customized by software, which shows brighter and brings more fun for customization. Please note: The RGB backlight does not come thru the keys. Hot-swappable Red Switch: High-quality PCB supports 3/5-pin hot-swappable, so you can enjoy the fun of making your own unique keyboard without soldering. Linear red switch, less mechanical sense, quieter, smoother and faster. Ideal for office use, for customer service and for those who like to type quietly and quickly. Triple Mode + Multi-device Connection: This hot swappable keyboard supports 3 connection modes, including USB-C wired mode, 2.4G wireless mode and Bluetooth 5.1 mode. Up to 3 devices can be connected via Bluetooth at the same time, and can be easily switched by the knob. Compatible with Win/Mac dual system, unlimited use. Multi-function OLED Smart Display and Knob: Royal Kludge M75 keyboard has built-in brand new OLED screen and rotary knob, making this wireless mechanical keyboard fun! Display functions: battery level, WIN/MAC, wired/2.4G/Bluetooth mode, volume level. Knob function: switch machine, volume adjustment, switch mode. 75% layout Gasket-Mount Mechanical Keyboard: This gaming keyboard features a gasket structure, which uses gasket material between the plate and keyboard housing on both top and bottom sides. It gives the board a slightly cushioned feel, which provides a consistent, softer, and more comfortable typing feel and pleg acoustic feedback.