International Watch Co., No. 6390, Movement No. 676384, Case No. 676501, Cal. 71-19H6, 51 mm, 96 g, circa 1917

An extremely rare Schaffhausen deck watch of the British Royal Navy - executed legendary "fishtail" caliber and centre seconds
Case: steel, polished, reeded screw back. Dial: enamel, Arabic numerals, centre seconds, "broad arrow", blued spade hands. Movm.: bridge movement so-called "fishtail calibre", frosted, gilt, chatoned, indirect centre seconds, "Patent 55231", screw compensation balance, index spring fine adjusting device.

Fishtail-caliber
This is one of the most successfull watch movement designs ever made. The aesthetical beauty of this construction is unmatched. At the same time, this is one of the rarest IWC-works, of which only 600 pieces were produced.