It will only let you know when it is time without disturbing your surroundings. In a variety of public places such as libraries, schools, theaters, restaurants, and other business scenes such as business business meetings and conferences. In Welfare welfare facilities such as hospitals, nursing, nursing, and nursing. In the noisy environment, strong vibrations will certainly notify you of the moment. Difficulty in hearing disorders, even in noisy environments, module no: MVA-01, analog quartz accuracy: average monthly ±20 seconds (normal temperature cellphone: 5 to 35 degrees Celsius), strong vibration alarm function, "GEKISIN VIBRATION ALARM SYSTEM" LED lighting battery (built-in) for watch operation: SRARM 626W Life : Approx. 2 years; Vibration alarm/Lighting: CR2032; Life Span: Approx. 2 years (but depends on frequency); Case Material: Stainless steel+synthetic resin; Reinforced resin with glass fiber; Band material: Urethane resin; Buckle: Stainless steel; Size: Case diameter; Width: 1.6 inches (40 mm); Case thickness: 0.7 inches (145 g); Waterproof performance for everyday use. Waterproof 1 year manufacturer **Country of Manufacture: China.