Omega caliber 3861

Caliber 3861 is an updated version of caliber 861 / 1861. It features a co-axial escapement and a silicon balance spring. It is Master Chronometer certified by METAS. Manual-winding chronograph movement with Co-Axial escapement. Certified Master Chronometer, approved by METAS, resistant to magnetic fields reaching 15,000 gauss. Free-sprung balance with silicon balance spring. Either gold plated finish or rhodium-plated finish, bridges with straight Geneva waves. BPH to be comfirmed