NSN 6645-00-250-4680 Intended use: Laboratory, photography, military. Great for dark room or night time use. 7 jewels. Manufactured in accordance with CID A-A-2580 and GG-S-764C, TY I, CL 2 0 to 30 minutes (30 min. register) 1/5 sec. divisions Large glow in the dark dial that is great for use in a dark room or for low light conditions Starts, stops and returns to zero by consecutive crown depressions Fiber-shell case (resists corrosion and erosion caused by acids) Dust and water resistant Anti-magnetic and shock resistant. 7 jewels Made to Government Specifications Government Purchase Item Description: Applicable Canadian Government NSN : 6645-21-870-5623 Stopwatch, 1/5 sec to 60 sec dial gradations, 30 min register, 1 sweep sec hand, controlled by stem push button, continuous running time, stem wound, open face, pocket type, metal case, white background, large black numerals and graduations, for use my military free-fall parachutists.