Up for grabs is a super clean Monolith M565C Closed Back Planar Magnetic Over Ear Headphones.

From Monoprice:

The Monolith™ M565C planar headphones are the perfect way to experience your music collection. Based on the M565, the M565C features a completely redesigned and engineered planar driver, producing a detailed aural landscape in a closed back enclosure. Spectacular imaging, low distortion, and perfectly balanced sound make the Monolith M565C a true audiophile listening experience.

Planar Drivers: Not your typical headphone driver! The planar driver in the M565C has been completely redesigned and engineered versus the driver found in the M565. Several enhancements have been made, including a new symmetrical magnet structure that allows the planar driver to be much more efficient in a closed back enclosure. The result is low distortion, improved linearity, and spectacular imaging in a closed back design.

Closed Back Design: Outside noise stays out and only the music stays in! The 565C delivers excellent audio isolation, allowing the sonic landscape to not be disturbed by the outside world, and the outside to not be disturbed by your music. This makes the M565C the perfect audiophile choice for those that may need to listen in less than silent environments.

Comfort: The Monolith™ M565C has been engineered to be comfortable for extended listening sessions. 

Model 29514
Style Closed
Transducer Type Planar magnetic
Magnetic Structure Asymmetry Asymmetry push‑pull neodymium
Magnet Type High grade N50 neodymium
Driver Size 66mm
Maximum Power Handling 2 watts (for 200ms)
Maximum SPL >120dB
Frequency Response 10Hz ~ 50kHz
Total Harmonic Distortion Less than 1% at 1mW; 1kHz
Impedance 18 ohms
Efficiency 96dB / 1mW
Optimal Power Requirement 1 watt
Weight 13.7 oz. (389 g)