Reference 5170J-001 marks the beginning of Patek Philippe’s contemporary take on the manually-wound, two-register chronograph wristwatch. Beginning production in 2010 and ceasing in 2019, the timepiece is appropriately sized at 39mm to fit an array of wrists. Interestingly, the dial features a 15 beat pulsometer scale which harkens back to doctor’s watches from the 1940s. Using the scale, the chronograph can be activated to help calculate the pulse of a person. It also adds an aesthetical value and is playful to what would normally be a standard dial from the manufacturer.