Shure SE310-A-EFS High Definition Sound Isolating Micro Speaker Earphone with Tuned Bass Port (White) Sound isolation technology blocks background noise for an ultimate listening experience Sound signature provides a unique acoustic sound to address specific listening preferences using Hi-Definition MicroSpeakers plus Tuned BassPorts Sound signature provides a unique acoustic sound to address specific listening preferences using Hi-Definition MicroSpeakers plus Tuned BassPorts Modular design allows for the use of variable cable lengths and the ability to add optional in-line accessories such as the Push-To-Hear ac Frequency range of 22Hz-19kHz