smartialarts 
Quick search shows these were last this cheap in 2020.
Over-ear design for maximum wearing comfort for long work sessions
Sophisticated open technology for spacious and airy sound without compromise
Patented Varimotion two-layer diaphragm for improved high-frequency range and better performance at low frequencies
Unique flat-wire voice coil for higher sensitivity, better impluse and treble response
Specifications:
Headphone type – open
Sensitivity headphones – 105 dB SPL/V
Rated Impedance – 62 Ohms
Detachable cable – yes
Cable Length – 3 m
Earpads replaceable – yes
Maximum input power – 200 mW
Audio frequency bandwidth – 10 – 39800 Hz
