Artec EPP Endpin Jack 1/4" w Integrated Preamp and Battery Box.  The original packaging has blemishes.  Shipping is included in the asking price.  

The Artec EPP is an endpin with a miniature preamp inside for a soundhole or piezo pickup of an acoustic guitar.

It takes a 2.5mm input jack from either a piezo or soundhole pickup. The pickup plugs straight in inside the guitar and the amplified signal is produced at the other end straight to the cable (standard 1/4 inch). 

Requires a 9v battery to run.