Offering a view of the beating heart of the El Primero Presented in a sleek 39. 5mm steel case Black dial with three counters, each in a metallic tone Measures and displays elapsed time with 1/10th of a second precision Driven with precision by the iconic El Primero 3604 movement REVEALING THE BEATING HEART WITHIN Bridging the past and present, the Chronomaster collection embodies the brands mastery of automatic, high frequency chronograph movement and the unique design language established over the course of 50 years. The Chronomaster Open exposes the beating heart of the El Primero movement in an unexpected way. A UNIQUE AESTHETIC Revealing the iconic movement hard at work within, this striking model features an open base plate and bridges, as well as an escape wheel and pallet lever crafted in lubricant-free silicone. Housed within a sleek 39. 5mm steel case, the matte black dial makes a bold statement with three counters in varying metallic tones - a 60-minute counter at 6 oclock