You must have at least one set of BLE Nano Kit v2 because you will need the companion board, DAPLink v1.5 board, which is used to load firmware into BLE Nano 2 from a PC.**Headers are soldered on, we have another model that comes with the headers un-soldered on.
Nano 2 (No Header)
BLE Nano 2 is the smallest Bluetooth Low Energy System-on-Chip (SoC) development board, only 18.5 x 21mm. You could develop application using Nordic's SDK, mbed.org or our open source Arduino Library for nRF5x.