Sennheiser HD 650 Open Back Over Ear Headphones (discount at checkout)

RRP of £249.99 and selling at other retailers for around £230, but a new non-refurb pair are only £200 at Sennheiser with its 20% off at checkout promotion.
The refurb version is also down to £184, but for an extra £16, you might as well get brand new with a 2 year warranty as opposed to a 1 year warranty for refurb.
Reviews:
Sennheiser HD 650 Updated open hi-fi over-ears – Headphonecheck.com
Sennheiser HD 650 Headphones Review – RTINGS.com
Sennheiser HD 650 vs HD 600 Review – Revisiting Classics in 2020 – Headphones.com
Sennheiser HD 650 Studio Headphone Review – Sonarworks.com
The HD 650 reproduces the subtle details in your music with the same confidence as the highlights.
Features
Open-back dynamic headphones
Special damping element made from fine acoustic metal mesh
Exclusive 42 mm transducer and 38 mm diaphragm
Lightweight, timeless design and comfortable velour pads for hours of fatigue-free listening
Frequency response: 12 41,000 Hz
Go-to reference for analytical listening
Extremely tight production tolerances ( 1 dB) and handpicked components
Detachable connecting cable made from highly conductive OFC copper
Impedance: 300 ohms
Total harmonic distortion: 0.05%