The Apple iOS version of the Sennheiser Momentum In-Ear Headphones offer a compact ear canal coupling design with a dynamic transducer, plastic-free acoustic components and stainless-steel sound tunnel to deliver a frequency response of 15 to 22,000 Hz, a THD of less than 0.5%, and a maximum SPL of 118 dB. The included Apple iOS in-line microphone and remote control allows you to make calls, adjust volume, and navigate tracks with ease. They feature a right angle 1/8" (3.5mm) plug for connecting to your smartphone or other mobile device, a premium carrying case, and a set of four (XS, S, M, L) ear adapters to accommodate ear canals of different sizes.