Chronometer medical 1960 42mm Mechanical Hand Winding A medical chronometer is a device designed to be accurate and reliable that was used in healthcare to precisely measure time intervals during medical procedures or laboratory experiments. Watch in perfect aesthetic and functional condition Fully original , The watch is unworn ,never used and really well preserved The is Movement Mechanical Hand Winding, keeps time perfectly and the charge lasts 30 hours (Tested) OPERATION Medical scales are those particular measurement scales which, printed on the dial of the watch, measure the time necessary for a certain number of heart beats or breaths, indicating the number per minute. A distinction is made between pulsometric and asmometric. The pulsometer scale is positioned along the external perimeter of the dial: after counting 30 heartbeats, you check the position of the second hand on the pulsometer scale which will indicate the number of beats per minute. The asmometric scale instead allows you to establish the number of breaths per minute. The times of 5 breaths are counted and then the position of the second hand is checked on the asmometric scale to read the number of breaths per minute. -Case : 42mm without crown ,stainless steel. -Dial: analogue, Silver color with numbers for pulsometer and asmometer ,golden color number and hands luminescent . -Glass: Plexiglass -Movement: Mechanical Hand Winding -Strap: Genuine leather strap 21 cm long adjustable. Watch only Registered and Insured shipping