Sennheiser IE500PRO sound-isolating, in-ear monitoring headphones offer “high-resolution, distortion-free sound with graduated tonal depths” 

Announced at the start of 2019, these IE500PRO in-ear headphones (also available in clear finish) are a level up from the IE400PRO (announced at the same time) – yet retain all the simple ‘ticks of the boxes’:

Stereo minijack, with a right-angle plug, all attached to a rugged, 1.3m cable – which is removable from the earbuds.

IE500PRO uses a ‘TrueResponse’ single high-performance dynamic driver – with a diaphragm measuring only 7 mm in diameter – covering the entire frequency spectrum. A system of magnets with triple-duct ventilation significantly reduces the distortion factor, and a two-chamber absorber in the direction of the ear canal minimises feedback peaks that would otherwise occur naturally. Even at high sound pressure levels, the sound remains clean and free from distortion. Note – the included cable is even more heavy-duty than what is provided with IE400PRO model.

The vitals:
Impedance: 16 ohms
Frequency response: 6 – 20,000 Hz
Sound pressure level: 126 dB
THD: < 0.08 % (1kHz, 94dB)
Cable length: 1.3m
Transducer principle: Dynamic
Weight: 18g
Attenuation: < 26 dB