Two versions of the Vacheron Constantin Historiques Cornes de Vache 1955 (both measuring 38.5 x 10.9 mm and powered by caliber 1142 ): Steel Hodinkee Edition ref. 5000H/000A with Pulsometer scale (2017) Platinum ref. 5000H/000P-B058 with Tachymeter scale

Inspired by the Harmony watches of fellow Vachonistas and the piece unique American 1921 recently introduced, I've reached into the vault for this feature on shaped watches. But first, an explanation of model numbers. Image credit Vacheron Constantin unle