The timer is mechanical and must be wound when setting. When setting even a short time, make sure to turn the guide to 55 first and then set the desired time. If the timer is not sufficiently wound, it will not sound. / Analog timers have a setting error. If you need precision, it is recommended to use a digital timer.Do not use in dusty locations.Not waterproof.Do not get wet.Do not disassemble or modify.Do not drop or hit.Stop use if deformed or damaged.Keep away from fire or heat.Use only as intended.