Its a friendly reminder to turn your phone to SILENT (NOT VIBRATE) when you enter the studio., WHY? , Because we often have private training or classes taking place in one side of the studio and We tested sunrise, wearable, and vibrating alarms to find the best silent alarm clocks for heavy sleepers and the hard of hearing. These options can help wake people up without disturbing the Amazon.com: Chest Percussion Cup for Adults Manual Physical Vibration Therapy for Sputum Break up, Phlegm Removal, Lung Expectoration Aid, Palm Silicone Self Aspirator Device (Small) : Health & Household How to Turn Off Vibration on Your iPhone