This is a used 3DR Air Radio Module. This came in a lot of miscellaneous drone parts that I aquired recently, based on some quick internet searches this appears to be part of the "3DR" series of radio telemetry modules. I found similarly designed modules on the Alibaba website.

It's marked 915MHz on the top. It has an antenna and a small 4-pin connector (Gnd, Tx, Rx, +5v). I power tested the unit by suppling 5vdc to the GND/5v terminals and it powers on (LED green). The other LED intermittently flashed red. No other testing was performed, I have no idea what received this unit is compatible with. This unit is being sold for parts purposes only.

Listing Includes: 

• Air Radio Telemtry Module - 915MHz
• Antenna