The Omega Genève Chronostop 146.012 is a notable vintage monopusher chronograph from circa 1969–1970. Often referred to as the "Jumbo" or "UFO" due to its oversized 41.5mm–42mm case, this specific reference was a specialized release primarily for the Italian market.

• Μηχανισμός: Features the Calibre 920 manual-wind movement, which includes a date complication. It operates at 21,600 vph with a 40-hour power reserve.

• ΚΑΣΑ: Stainless steel "Dynamic-style" oval case, measuring approximately 42mm in diameter and 48mm lug-to-lug.

• Καντράν: This model features a rare blue dial with a date aperture at 3 o'clock. Standard variants often came in grey or silver.

• Chronograph Function: A "stop-second" monopusher system designed for short intervals (under 60 seconds). You press the pusher at 2 o'clock to start, and must press and hold it to stop and read the time, then release it to reset the hand to zero.

• ΜΠΡΑΣΕΛΕ: Typically paired with an integrated stainless steel bracelet (Ref. 1153/138)

• Rarity: The Calibre 920 (with date) is significantly rarer than the no-date Calibre 865, with only about 61,000 units produced.