The MM 30i Noise-Isolation In-Ear Stereo Headphones with Mic from Sennheiser are designed to put you directly in touch with your music and calls. Each earpiece has a dynamic speaker that provides clear, natural audio with a wide frequency response and excellent bass performance. Multiple sizes of eartips are provided, letting you find the best fit to create a seal in the ear canal that blocks out unwanted ambient noise. This makes the headphones ideal for use in loud environments, such as airplane cabins.