This is an RTL SDR blog software defined radio receiver with RTL2832U ADC chip, R820T2 tuner, 1PPM TCXO, SMA F connector and aluminium case with passive cooling. Tunes from 500 kHz to 1.7 GHz with up to 3.2 MHz (2.4 MHz stable) of ( HF works in direct sampling mode). Perfect for use as a computer based radio scanner with free software like SDR#, HDSDR, SDR-Radio, GQRX or SDR Touch on Android. Works on Windows, OSX, Linux, Android and Computers like The Raspberry Pi.

Great for many applications including general radio scanning, air traffic control, public safety, ADS-B aircraft radar, marine AIS, ACARS, trunked radio, P25/MotoTRBO digital voice, POCSAG, weather balloons, APRS, NOAA APT/ Meteor M2 weather satellites, radio astronomy, DAB, or as a low cost panadapter with a ham radio. 

This RTLSDR model has several improvements over other brands. It uses the improved R820T2 tuner, a 1PPM TCXO, better components, a redesigned lower noise PCB, cooling improvements, extra ESD protection and an SMA F connector. It also has a software activatable bias- Tee for powering LNA's and active antennas. Full info available on the improvements a  goo.gl/MD12bD.