The Marathon CSAR Chronograph Watch is a Swiss-built genuine military issue Tritium/H3 watch (with NSN) that can easily meet the needs of pilots, air crews, professional divers, military operators, search and rescue team members, and anyone else that appreciates a rugged, hand-built watch.FEATURES AND SPECIFICATIONS OF THE STAINLESS STEEL CHRONOGRAPH:Engraved date of production and serial numbers for traceability and maintenance on back2 Scale dial shows standard and supplemental (24hr) time 1-12, 13-24Revolving external bezel is calibrated from 0 to 60 in white on black backgroundSweep Second hand indicates timing in 1/5 sec ( and/or 1/100 minute) up to 60 secChronograph includes time-out 2 button function: independent start/stop & zero/resetIncludes hand-rubbed lacquer storage & display boxA Pilot Chronograph That Divers Will LoveCommonly referred to as the Marathon “CSAR” (Chronograph Search and Rescue), this Marathon automatic pilot watch has chronograph timing capabilities, but is also a Dive Watch. With 300m/1000ft water resistance, the screw-down crown and screw-down side pushers prevent water from entering the sapphire crystal and 316L stainless steel case.The Swiss-made movement is 7750 ETA Valjoux Automatic (self-winding) 25 jewel minimum, non-magnetic, and has 36 hour minimum running time. Date & Day display on the dial includes rapid date and day correction. Register indexes & hands use MaraGlo paint for night viewing, and encapsulated tritium (isotope H3) light sources are used for dial at each hour position, and on the hour and minute hands. Tritium activity is between 28-30 millicuries.Marathon CSAR FeaturesThis tritium chronograph’s case diameter is 44.5 mm, and the high turning bezel is 46.6mm. Timing is dual graduated – inner graduations are 1/5 sec and decimal 1/100 minute timing on the alternate inner timing ring. The watch comes complete with 22m wide 100% vulcanized black rubber strap & 316L stainless steel buckle.The Marathon Pilot Chronograph wristwatch meets the specifications for NSN 6645-01-544-0408 and NSN 6645-20-002-8253 (6645015440408 and 6645200028253). The chronograph includes a small sweep second (at 9 o’clock position), a 30 minute register at 12 o’clock position, and a 12 hour register at 6 o’clock position.