1 Bluetooth 4.0 Low Energy - BLE Shield v2.1 (nRF8001)
2 Bluetooth Low Energy (BLE 4.0) nRF8001 breakout
1 BLE Nano & MK20 USB Board (nRF51822)
http://www.antratek.nl/bluetooth-4-0-low-energy-ble-shield-v2-0
http://redbearlab.com/bleshield/
http://www.seeedstudio.com/depot/Bluetooth-40-Low-EnergyBLE-Shield-v21-p-1995.html
http://www.kiwi-electronics.nl/bluefruit-le-bluetooth-low-energy-ble-4-0-nRF8001-breakout
http://www.antratek.nl/ble-nano-mk20
http://redbearlab.com/blenano/
https://www.nordicsemi.com/eng/Products/Bluetooth-Smart-Bluetooth-low-energy/nRF51822