The nice!nano is a Pro Micro drop-in replacement board that makes building wireless keyboards a breeze. For more details and documentation, visit Nice Keyboards. You'll likely want a battery as well as sockets to go with your nice!nano. Ultra Low Power Built using power-conscious design and parts, the nice!nano stretches battery life to its limits. Super Thin With a mid-mount USB-C port, the nice!nano is only 3.2mm thick. That's thinner than a Pro Micro. Drag and Drop Programming The included UF2 bootloader makes updating the firmware as easy as dragging and dropping a file. No extra software required. Tech Specs  Microcontroller Nordic nRF52840 Flash 1MB RAM 256KB GPIO Pins 21 Battery Charger 4.2V Lithium @ 100/500mA Voltage 3.3V Quiescent Current ~20μA PCB 2U" ENIG, TG 170 FR4