The Patek Philippe Ultra-Thin Refe. 5180 is an awe-inspiring work of engineering on display in a very comfortable and wearable watch. The watch beautifully displays the ultra-thin, self-winding caliber 240 which celebrated its 40th anniversary in 2017. This gorgeous movement is hand engraved which alone takes about 130 hours of work. This example is unworn and complete with original box and papers.