Tetra Duo

The NOMOS Tetra 27 Duo 405 is the two-hand version of the compact Tetra, with a 27.5mm square stainless steel case, a white silver-plated dial, gold-coloured hands, and a closed stainless steel case back. Introduced in 2019 as part of the NOMOS Duo series, this reference originally used the Alpha.2 movement and was rated to 3 atm. The current specification lists the DUW 4001 Duo and 5 atm water resistance. The case measures 27.5mm by 27.5mm, with a height of 6.1mm and a lug-to-lug length of 38.5mm. It has a sapphire crystal front and a closed stainless steel back. The Tetra case is defined by its square shape, compact proportions, and stepped lugs, while the absence of a small seconds display gives the watch a more reduced layout than the standard Tetra 27. The galvanized white silver-plated dial uses the Tetra’s square minute track and printed markers, with mocha-brown typography noted in NOMOS’ description. The display is limited to central hours and minutes, indicated by two gold-coloured hands. Power currently comes from the NOMOS DUW 4001 Duo, a manually wound in-house calibre based on the DUW 4001 and adapted for smaller two-hand models. It measures 10 ½ lignes in diameter and 2.6mm in height, with 17 jewels and a power reserve of up to 53 hours. The watch is supplied on a beige vegan velour remborde strap with an 18mm lug width.