This is the Frisky D4R-II 2.4 GHz Radio Receiver.

This receiver works great with FrSky Radios and it features PPM output for a simple 3 wire hookup to translate 8 channels.

The unit also features Telemetry.  This includes support for 1 analog sensor and 1 digital input such as that from a Naze32 Flight controller.

These are perfect for mini quadcopters such as the QAV250 or Blackout Mini H quads.