Sennheiser IE 300 Premium Wired In-Ear Monitor HeadphonesFor natural balanced sound With a host of innovative acoustic technologies that supercharge our 7mm TrueResponse transducer, the IE 300 creates an effortless audiophile listening experience wherever you want one. Detailed Sound Everywhere The driving force of the IE 300 is a refined version of our 7mm TrueResponse transducer. A new blend of materials in the diaphragm improves its rest and response times for greater accuracy throughout the frequency