Known as the Auto Rallye “Decimal,” this variant of the Heuer-produced timer is fitted with a more complex dial, capable of measuring fifths of seconds, and hundredths of minutes. In an age where a seldom-used app on your iPhone can relay more information with greater precision, this might not sound all that significant, but when attempting to shave fractions of seconds off point-to-point times in the ’50s, this tracing detail made all the difference. Moreover, the decision to apply luminous compound on the dial and hands also proved useful to drivers, allowing them to make use of the instrument with ease.