TAG Heuer Calibre 1887

TAG Heuer's Calibre 1887 is an automatic column-wheel chronograph based on the Seiko TC78 platform. Announced in 2009 and released in 2010, it features the oscillating pinion originally patented by Edouard Heuer in 1887. While marketed as in-house, it was controversially revealed to be based on a licensed Seiko design, though TAG Heuer made significant modifications including a larger diameter, thinner profile, Swiss assortment from Nivarox, and KIF shock protection. The movement was discontinued and replaced by the Heuer 01 and Heuer 02 calibers.