Servicing a watch can be very hairy. These pictures/video show hair in a watch movement attached to the wheels. When enough hair gets inside, it literally wraps around the wheel pivots and pinions. As you can see, it does quite a job adhering to the escape wheel. Given the low power levels and very tight tolerances inside a watch, hair inside a watch movement can cause significant running issues. Once hair makes it deeply into the movement and train, the only effective means to remove it and assure future strong performance is full disassembly. You simply can’t know where it has gone. Hair can be introduced during servicing without the proper clean environment and lack of air (suction or blowing, I prefer suction) available at the bench to keep parts and the movement clean. I have suction at three workstations and air blowing ability at a fourth. Also parts must be covered during servicing once they are cleaned so they do not attract dirt. You will see glass and plexiglass covers in many of the pictures in my posts. This is one reason why there is no “quick job” when opening the case of a watch for servicing or a repair. You need to assure a clean room environment and heavily inspect the movement while exposed and before sealing it (and performing water resistance testing if required.) Visit the ClockSavant Instagram page to see a video showing how well adhered hair is to the escape wheel in this watch.