Stainless steel Speedmaster, reference 105.003 'Ed White' chronograph wristwatch. Made 1966

The reference 105.003 was introduced in 1963 and was the fourth generation of Speedmaster pre-professional models. It was the first one produced exclusively with baton hands (instead of Alpha hands) and it was also the last Speedmaster produced without crown guards. The case back features the initials C.H. engraved in small cursive font beneath the hippocampus.

In 1962, NASA put out the call to 10 watch brands to submit mechanical chronograph wristwatches in a bid to become the official supplier for the astronauts. Out of all applicants, the Speedmaster was the only watch that passed all of the rigorous testing inflicted on the watches. In 1965, The the reference 105.003 was officially selected by NASA.  

NASA astronaut Ed White was wearing a Speedmaster, reference 105.003 during a spacewalk in 1965. It was subsequently selected and certified to become the official NASA wristwatch for EVA (Extravehicular activity - is any activity done by an astronaut or cosmonaut outside a spacecraft beyond the Earth's appreciable atmosphere) activities.

Other design features included a variety of bezel inserts: A Tachymeter (to calculate speed), Pulsometer (for medical professionals to measure pulses), Telemeter (to calculate distances in meters), Telemile (to calculate distances in miles) or Decimal (for industrial timing, statistical analysis, calculation of averages.)

The 105.003, remained in production until 1969 due to low initial sales figures. Clients preferred the new style of asymmetric cased Speedmasters (references ST105.012 and subsequently ST145.012) which were being sold concurrently.