How to use the NRF52840 Dongle (PCA10059) as development board – JimmyIoT
nRF52840 MDK USB Dongle (PCBA) – makerdiary
nRF52840 USB Key with TinyUF2 Bootloader - Bluetooth Low Energy [MDBT50Q-RX] : ID 5199 : $15.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Amazon.com: nRF52840 Micro Dev Kit USB Dongle : Electronics