NIVADA GRENCHEN Chronomaster Aviator Sea Diver Vintage - Men's wristwatch - Rare, antique Cal. Valjoux 23 (The 22 and 23 calibres have been also used by Vacheron and Patek) Era: Circa 1960 Equipped with the prestigious hand-wound Valjoux 23 calibre movement with a column wheel Steel casing, 39 mm in diameter excluding crown, 42 mm including crown. Bidirectional bezel, push-buttons Black Panda Dial (see photos) Perspex crystal Screw-down caseback Leather stral (NOT Nivada) See photos Strap length 24 cm No box or papers. The watch is used, in excellent condition and perfect working order. Insured shipping with tracking via express courier.