This Arnold and Grand Complication Sir John Men's watch features a 45mm-diameter case, thickness 11.46mm, see-through case-back secured by 8 screws with royal marine crown-symbol and engraved limited edition number. Very high grade finish, bridges and plates in plated black gold, finely sand-blasted. The sunburst pattern is obtained through sand-blasting and diamond-polishing on the bridges surface. Screws, "barrettes" and bridges of tourbillon in polished steel. Flange bezel in rose gold. This Arnold and Son Grand Complication Sir John Men's watch also features manual tourbillon movement, exclusive Arnold & Son calibre A1767, 21'600 vibrations per hour, domed sapphire glass with anti-reflective coating on both sides, sapphire see-through case-back secured by 8 screws, and a large scale genuine alligator strap with folding buckle clasp. This watch is water resistant to 50 meters / 150 feet.