The in-ear headphones come with individually adjustable flexible ear hooks, as well as silicone and memory foam ear adaptors in three sizes (S/M/L). The IE 300’s supplied 3.5mm cable is reinforced with para-aramid for stability. For additional strain relief, the gold-plated Fidelity+ MMCX connector is seated in a recessed, 4.8mm-wide socket in the housing. Balanced cables with 2.5mm or 4.4 connectors are also available as optional accessories. A premium carry case is included for storing the headphones safely.
The headphones come powered by a “refined version” of Sennheiser’s 7mm Extra Wide Band (XWB) transducer, manufactured at the company’s headquarters in Germany. The components include an optimised membrane foil to minimise natural resonances and total harmonic distortion (THD