The Rolex Milgauss is one of the most fascinating technical achievements in the Rolex catalog, a watch designed specifically for scientists and engineers working in environments of intense electromagnetic fields. Introduced in 1956, the Milgauss — the name referencing resistance to 1,000 gauss of magnetic force — was developed in collaboration with CERN, the European nuclear research organization near Geneva. Rolex engineered a soft-iron Faraday cage within the movement to shield the escapement and balance wheel from magnetic interference, a challenge that had rendered standard mechanical watches unreliable in laboratory settings. The original ref. 6541, with its distinctive mesh bezel and lightning-bolt seconds hand, is now a serious collector piece. After a hiatus, Rolex reintroduced the Milgauss in 2007 with ref. 116400 and 116400GV — the latter featuring a stunning Z-Blue or green sapphire crystal with a subtle green tint that has become the model's most iconic modern element. Pre-owned Milgauss watches remain among the more attainable and underappreciated references in the Rolex sport lineup. DeMesy & Co. in Dallas has been sourcing and authenticating pre-owned Milgauss references since 1987.