?Programmable & Compatible with Win/Mac OS? The GK75 keyboard is designed for compatible with both Win and Mac OS. With the software, you can create macros and remap the keys and even the knob freely. The built-in flash memory makes sure to save the setting at offline mode. No worries of losing it. ?High-quality PBT Keycaps in GK5 Profile? The GK75 keyboard adopt the PBT material for keycaps, which is proved to be sturdy and oil-proof even after long time use. Being GK5 profile, the keycaps can keep the typing angle ergonomic and also fit the north-facing LEDs without any interference. ?Gateron Optical Switches? The Gateron optical switches are 1-pin switches. Unlike the traditional mechanical switches, the optical switches are triggered by laser though the contact point. In this way, they can last longer than general mechanical switches. With the keyboard of GK75, there are linear yellows, reds and blacks as well as tactile browns for choosing. ?Innovative Shallow Gasket-Mounted & Bottom Foam?Shallow Gasket design is the first Shallow Gasket structure around the world that comes with an all-in-one silicone pad. Apart from eliminating traditional design's drawback of lacking support on main typing area, Shallow Gasket silicone pad can cushion shock under every keystroke by being inserted in between PCB board and plate. The keyboard also contain a foam at bottom layer to reduce hallow sounds, as well as enhancing feeling of typing stokes. ?75% Hotswap Keyboard with a Rotary Knob?GK75 keyboard is equipped with hot swappable terminals, with which you can install optical switches directly without soldering. Being 75%, the keyboard turns the home clusters into one column of the commonly used home/delete/pgup keys, saving much space for the mouse. Adding a rotary in the end of the F row, the keyboard can fulfill changing volume by simply rotating left and right. Note: Hotswappable with Gateron optical switches only.