Automatic chronograph movement, Calibre El Primero 4061 base. Stainless steel case with fixed bezel and black sunray dial featuring a skeletal display. Luminous silver-tone hands and index hour markers, minute markers on the tachymeter ring. Includes column wheel mechanism, central second hand, small seconds sub-dial. Two additional chronograph sub-dials displaying 12-hour and 30-minute elapsed time. Sapphire crystal with scratch resistance. Deployment clasp closure. Water resistant up to 100 meters / 330 feet. Approximately 50 hour power reserve. Composed of 282 parts containing 31 jewels, beating at 36,000 vph.