I will send it from Ginzo PR because the watch studio is very busy. Also today, if you look at it ... then if you put the clock on the main subject ... it will be black like this Watch studio The cause is the dirt accumulated between the frames of breath. Especially in summer, sweat often accumulates, so accumulated dust absorbs sweat and hardens. In that case, it is not possible to clean every corner with a brush or running water. There is no breakdown, so it is not necessary to disassemble and clean, but there should be a surprising number of people who want to be able to get rid of it anyway. Summer yogure is persistent, and it gets into the gap of the breath and the back lid. Such dirt will be beautiful if you disassemble the exterior once and put it on an ultrasonic cleaner. For example ... Such a dirty watch ... When you try ultrasonic cleaning, it becomes very beautiful like this. The vibration of the ultrasonic waves generates micro bubbles in the water, and the shock waves that are emitted at the moment the bubbles burst break up the dirt in the fine gaps. Since mechanical watches are extremely delicate, we recommend this ultrasonic cleaning. In addition to cleaning, it is good to do maintenance regularly.