Bestbuy offers 8BitDo - Wireless USB Adapter 2 for Most Gaming Controllers - Black for $15.99 (orig. $19.99) with free shipping.

Product Description:
Compatible with all 8BitDo Bluetooth controllers. Next Gen too. Connect nearly all wireless controllers to your Switch, Windows, macOS, Raspberry Pi and more. 

• 8BitDo Ultimate Software
  Ultimate Software gives you elite control over every piece of your controller: customize button mapping, adjust stick and trigger sensitivity, vibration control and create macros with any button combination. Create controller profiles and switch between them at any time.