HiFiMAN HE-6 pla

This particular pair is just back from the factory after being refreshed and having the pivots for the earcups replaced. There is some cosmetic damage but they are otherwise in perfect working order.
Description
Considered by many to be the world‘s finest headphone, without regard to price, the HIFIMAN HE-6 features the company‘s proprietary planar magnetic technology in a no-compromise design. With sensitivity of 83.5dB, the HE-6 must be paired with a headphone amplifier of comparable quality such as the HIFIMAN EF5 which delivers 2 watts per channel. The HE-6 is the reference choice of critical listeners around the world. HE-6 requires a powerful headphone amplifier to drive it. Our EF6 headphone amplifier can serve 5 watt per channel at 50 Ohm.
ACCESSORIES Custom 4 pin XLR cable from best in the verse cables

Specification Frequency Response : 8Hz -65 KHz  Sensitivity : 83.5dB  Impedance : 50 Ohms  Weight : 502 g  Cable Length : 2 m  Plug : 6.35mm