BenQ has detected that a small percentage of their EC-B series mice produce a noise which is noticeable to some users. The company narrowed down the issue to the high frequency vibrations caused by the Avago 3360 sensor and other internal components. These vibrations, which don't affect the mice's performance, are also harmless to the human body. The issue has been addressed and will not affect future products. But since customer comfort and satisfaction are important to BenQ, the company is offering replacement mice starting mid-March. EC-B mice owners who suffer from the noise issue can contact BenQ's service center directly for further assistance.