They are small enough to fit in just about any pocket. And they shorten the distance between you and the sound more than any other headphone design. In order to sound really great, however, they need to have a snug fit. Different sizes of ear adapters do the trick, just as well-designed hooks. High-quality in-ear headphones are the perfect choice for travellers or in the gym.
Sennheiser offers a wide range of in-ear models: From state-of-the-art audiophile ones to water resistant sports models. There are also Bluetooth® or wired headsets with integrated remote controls - an ideal choice when you want to sonically upgrade your smartphone.