The sensor window on the left earbud of SoundSport Pulse wireless headphones should be wiped with a damp cloth after every three to four uses for best performance. While the entire earbud doesn’t require scheduled cleaning, occasional cleaning may be needed. If exterior surfaces of the earbud need to be cleaned, gently wipe with a slightly moist cloth. Be careful not to allow any moisture to enter the headphones through the ports or the USB connector. (Cleaning the door covering the USB with a moist cloth is acceptable.) In addition, be certain not to force any dirt or debris into the ports. Do not blow air into or vacuum the ports or nozzle.