Hublot Big Bang Unico Sapphire Special Edition Asia Valjoux 7750 Automatic Movement, 28800bph with Working Chronograph & Decorated Bridges/Plates & Rotor to HUB1242 Movement  45mm 17mm  Black Skeletonal Dial with Numeral Markers  Solid Stainless Steel 316L  Black Rubber Strap with Deployant buckle FRONT GLASS:  Sapphire Crystal with Colorless Double AR Coating (Swiss Grade)  Display Case Back with Detailed Engraving Solid Stainless Steel 316L Bezel CLASP TYPE:  Deployant Buckle At 4:30 Position (Adjusted via Crown) Waterproofed to 30m direct from Factory