GMMK1, which stands for "Glorious Modular Mechanical Keyboard 1", is a product from Glorious PC Gaming Race. This keyboard is known for its full modularity, meaning users can easily swap out the mechanical switches without the need for soldering. It is ideal for experimenters and enthusiasts who want to try different switch and key combinations. The GMMK1's premium design and wide customization support make it a popular choice.