This is a sound-isolating hands-free earbud microphone that can be connected to an external connector with a charging and earphone microphone connection terminal in one location for your docomo-FOMA and SoftBank-3G phone. Comes with 3 sizes (S/M/L) earpieces that can be changed to fit the shape of your ears. It comes with a handy and smart cord retrieval reel that allows you to retrieve the cords in the way. The switch allows you to control incoming calls and calls (except some models) without touching your phone. (Requires longer press operation for more than 2 seconds)