40mm Tantalum case, 5.80mm thick, tantalum crown. Automatic manufacture BVL Calibre 305, hours and minutes, retrograde date, day, month and retrograde and leap year. Power reserve is 60hrs Unique piece To be offered at Only Watch 2021 auctions conducted by Christie’s on Nov 6, 2021 Estimate 80,000-120,000CHF Sold for 220,000CHF