Unimatic · Microbrand · Italy

Unimatic Modello Quattro U4S Bronze

Ref. U4S-BRZ · Limited · 2022 · Field

Unimatic Modello Quattro U4S-BRZ-ML Massena LAB
Photo: Unimatic
  • Unimatic Modello Quattro U4S-BRZ-MLL Massena LAB
  • Unimatic Modello Quattro U4S-BRZ-SI Swiss Institute
  • Unimatic Modello Quattro U4S-MEOB Claesson Koivisto Rune
From $895 to $1,268
  • Sellita SW200-1
  • 40 mm × 12.75 mm
  • Sapphire crystal
  • 300 m water resistance

Movement

Type
Automatic
Tier
Upper
Complications
Hours, Minutes, Seconds
Frequency
28,800 bph
Power reserve
41 h
Hacking
Yes
Accuracy (factory)
—

Case

Diameter
40 mm
Lug to lug
49 mm
Thickness
12.75 mm
Lug width
22 mm
Material
Bronze (CuSn8)
Hardening
—
Water resistance
300 m
Crown
Screw-down
Case back
Solid, screw-down
Bezel
Fixed
Finishing
Brushed

Crystal & dial

Crystal
Sapphire
Shape
Flat
Anti-reflective
Inner
Lume
Super-LumiNova GL light old radium (U4S-BRZ-ML, MLL; none stated on the U4S-BRZ-SI and U4S-MEOB)

Bracelet

Bracelet
—

Straps

Strap 1
Other, Foliage green TPU two-piece strap with a brushed bronze buckle signed UNIMATIC (U4S-BRZ-ML; the extra strap on U4S-BRZ-MLL)
Strap 2
Leather, Leather strap with a brushed bronze buckle signed UNIMATIC: milk shake distressed leather (U4S-BRZ-MLL; the extra strap on U4S-BRZ-ML), black Cordovan shell (U4S-BRZ-SI)
Strap 3
Other, King red TPU two-piece strap with a brushed bronze buckle signed UNIMATIC (U4S-MEOB)

Weight

Head only
—
On bracelet
—
On strap
—

Prices

VariantConfigurationTypePriceUSDAs ofSource
U4S-BRZ-ML Massena LAB—Msrp895 USD$8952022-12-14link
U4S-BRZ-MLL Massena LAB—Msrp995 USD$9952022-12-14link
U4S-MEOB Claesson Koivisto Rune—Msrp1,130 EURincl. VAT$1,2682026-10-25link

Variants

NameReferenceDialConfigurationStatus
U4S-BRZ-ML Massena LABU4S-BRZ-MLfoliage green, GL light old radium lume, bronze metallic open seconds rail and trims, foliage green phantom ladder hands, bronze metallic seconds tip, no datefoliage green TPU two-piece strap + milk shake distressed leather strap, bronze bucklesLimited (400)
U4S-BRZ-MLL Massena LABU4S-BRZ-MLLdeep burnt peat tapisserie made by hand in Italy, tone-on-tone signature, hand-applied GL light old radium lume, metallic gold phantom ladder hands, lumed seconds tip, no datemilk shake distressed leather strap + foliage green TPU two-piece strap, bronze bucklesLimited (99)
U4S-BRZ-SI Swiss InstituteU4S-BRZ-SIgalvanic black, hand-engraved by King Nerd with the William Tell apple, arrows and ribbon, skeletonized bronze phantom ladder hands, no dateblack Cordovan shell leather strap, bronze buckleLimited (1)
U4S-MEOB Claesson Koivisto RuneU4S-MEOBcircular brushed oxidised bronze, no markers, acid-etched logo, king red trims, brushed oxidised bronze skeleton ladder hands, king red seconds hand, no dateking red TPU two-piece strap, brushed bronze buckleLimited (50)

About this entry

80% of key specs known. Missing: weight, hardening, bracelet offered.

The Modello Quattro U4S in bronze (CuSn8 on the Massena LAB editions), Unimatic's first bronze case, made with New York's Massena LAB in 2022 on the same Sellita SW200-1 as the steel U4S, each edition recorded as a variant. Unimatic notes that the bronze oxidises and changes colour over time. Common specification, from Unimatic's spec sheets for the U4S-BRZ-ML, MLL and SI: 40mm brushed CuSn8 bronze case, 49mm lug to lug, 28.4mm case opening, 22mm drilled lugs, fixed monoblock bezel, 8mm screw-down 'Alchemical Sun' crown between crown guards (photos), screw-down caseback (titanium on the ML and MLL), 2mm thick in the descriptions, individually tested to 300m, 2.8mm flat sapphire with anti-reflective coating on the inner side. The U4S-BRZ-SI sheet gives a case thickness of 12.75mm, recorded, against 12.4mm on the drawings of all three sheets, in the pages' highlights and in Worn & Wound's launch report; neither figure says whether the crystal is included. No weight is published. Unimatic quotes the SW200-1 (26 jewels) at +/-12 s/day up to +/-30 s/day, 38h power reserve and antimagnetism to 4,800 A/m, without naming a grade or claiming regulation. None of the editions shows a date window (photos), so complications are hours, minutes and seconds. Unimatic's store shows 0 for the three sold-out Massena LAB editions; the ML and MLL were sold only through Massena LAB's website, so their prices are the US-dollar launch prices from Worn & Wound. Edition details. U4S-BRZ-ML (2022, 400): foliage green dial with GL light old radium lume, bronze metallic trims and seconds tip, foliage green hands, Octopus titanium caseback, foliage green TPU strap plus a milk shake distressed leather strap; Worn & Wound gave an edition of 200, where its page and sheet give 400, recorded. U4S-BRZ-MLL (2022, 99): hand-made Italian tapisserie dial in deep burnt peat ('bronze-like' in its description) with a tone-on-tone signature and hand-applied GL light old radium lume, metallic gold hands, Unimatic x Massena LAB titanium caseback, milk shake distressed leather strap plus a foliage green TPU strap. U4S-BRZ-SI (2022, 1), a piece unique made with Massena LAB and the artist King Nerd for New York's Swiss Institute: galvanic black dial hand-engraved by King Nerd with the William Tell apple, arrows and ribbon, skeletonized bronze hands, black Cordovan shell leather strap; it was sold at a Phillips charity auction for 12,600 USD (Worn & Wound), so no retail price is recorded. U4S-MEOB (2023, 50) is the bronze piece of the 'Ore' capsule that the Swedish architects Claesson Koivisto Rune designed for the opening of Unimatic's Milan flagship store, released there during the April 2023 Salone del Mobile (designboom), with the steel U4S-MEOS (Modello Quattro U4S) and the 18K gold U4S-MEOG (Modello Quattro U4S Gold); its page links no sheet and its description names no alloy, giving a thin bronze case, 2mm screwed-in caseback, 8mm crown, 300m, flat anti-reflective sapphire and the SW200-1 b with 38h: circular brushed oxidised bronze dial without markers, acid-etched logo and king red trims, brushed oxidised bronze skeleton ladder hands, king red seconds hand, no lume mentioned, UNIMATIC x Claesson Koivisto Rune caseback, king red TPU strap with a brushed bronze buckle; the price is the euro price for Italy, VAT included, still shown on its sold-out page.

Last verified: 2026-10-25. Edit or correct this entry.

Sources