Swiss made automatic movement, modified and personalised at U-BOAT specifications Frequency: 28.800 vibrations per hour, 4 Hz Jewels: 26 Power reserve: 44 hours Functions: hours, minutes, seconds, date Stainless steel AISI 316L case Case diameter: 47 mm Case back: screwed in, fumé glass showing the skeleton balance wheel Screw-down crown, positioned underneath the massive crown cap (protected as a Trade Mark), and automatic and helium escape valve High quality sapphire crystal with anti reflective treatment WATER RESISTANCE: 100 M, 10 ATM Laser cut strap handmade from hand-finished calf leather and processed according to traditional artisan techniques to give the strap a naturally distressed look and feel, brown color Strap width: 23/22 mm