Open Secrets: Making a Case for these 5 Stunning Casebacks

Like watch faces, casebacks can be irresistibly charming in their own unique way, especially when a sapphire crystal window reveals the inner workings of a timepiece. A caseback can also be intricately engraved with a story or a motif.

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In recent times, several watches have bowled us over with their intriguing casebacks. GMT India takes a closer look at five such masterpieces.

Royal Oak Perpetual Calendar “John Mayer” Limited Edition

With classic design elements, the Royal Oak Perpetual Calendar "John Mayer" Limited Edition 26574BC is steeped in historical significance. This watch, measuring 41 mm in diameter and 9.5 mm in thickness, features a white gold case with brushed and polished surfaces, embodying the iconic RO shape. The sapphire caseback, inscribed with "Royal Oak Quantieme Perpetuel" and "Limited Edition of 200 Pieces", reveals the watch’s intricate inner workings. At its core beats the calibre 5134, introduced in 2015, adapting the perpetual calendar to the classic 2120 base. Dating back to 1967, this base movement, central to the Royal Oak Jumbo 5402ST, is not the latest one though. With the debut of the 16202ST Jumbo featuring the calibre 7121, it's fitting for AP to consider upgrading their perpetual calendar models. This marks the end of an era, evident through its distinctive caseback.

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TAG Heuer Carrera Chronograph Tourbillon

TAG Heuer expanded its offering of teal green-coloured models this year, already present in the Carrera Chronograph series, to include the new Tourbillon model, creating what has been described as “a sophisticated statement piece”. Last year, to celebrate the 60th anniversary of the iconic Carrera chronograph, TAG Heuer unveiled the Carrera Glassbox and a 42 mm Carrera Chronograph Tourbillon, characterised by its seamlessly integrated domed sapphire crystal. At its core, the TH20-09 in-house movement and the rhodium-plated tourbillon are a testament to the Maison’s technical mastery and innovation. The inner workings of the Carrera Chronograph Tourbillon can be glimpsed through the screw-down sapphire crystal caseback, unveiling the self-winding TH20-09 column-wheel chronograph calibre with a tourbillon regulator—an evolution of the Heuer 02 introduced in 2016. Expertly redesigned under Carole Forestier-Kasapi's guidance, the enhanced movement now features bidirectional winding capabilities while maintaining a 28,800 vibrations/hour rate and a 65-hour power reserve.

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IWC Portugieser Chronograph Year of the Dragon

To honour the Chinese New Year, IWC creates a limited-edition Portugieser each year. This classic stainless steel build boasts sweet spot 41 mm sizing and contrasts it with a rich burgundy dial. Gold-plated hands and indices subtly create a two-tone appearance. Powering the chronograph is the IWC-manufactured 69355 calibre, a robust mechanical movement in a classic column-wheel design. Through the transparent sapphire caseback, one can admire the gold-plated rotor of the automatic winding system, designed in the form of a beautifully detailed dragon. Completing the homage, the caseback ring features an engraving of “2024 YEAR OF THE DRAGON”.

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Omega Speedmaster Moonwatch Professional White

The Speedmaster Moonwatch, part of all six moon landings, is an icon in every sense of the term. Crafted from stainless steel, this 42 mm marvel features sapphire crystal glass. Beneath this crystal lies the heart of the watch, the OMEGA Co-Axial Master Chronometer Calibre 3861. This movement powers functions including the small seconds subdial, the 30-minute recorder, and the 12-hour recorder, alongside the central chronograph function. Accredited as a master chronometer by METAS, the caliber 3861 movement upholds Omega's legacy of precision and reliability. The caseback reveals the finely finished surfaces, the rhodium-plated components, and the Geneva stripes adorning the movement. With Omega's proprietary Co-Axial escapement and a resistance to magnetic fields measuring up to 15,000 gausses, the caliber 3861 operates at a 3Hz frequency and delivers a 50-hour power reserve, ensuring unparalleled performance. 

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Tissot PRX Powermatic 80 Damian Lillard Special Edition 

Reflecting basketball star Damian Lillard's journey and character, Tissot's latest iteration of its successful sporty-chic watch, PRX, distinguishes itself with the intricate narrative it weaves. Echoing the bold design and colour scheme of last year's gold PVD-coated PRX Powermatic 80, this watch blends elements of sports and music, both close to Lillard's heart. Flipping the watch over, the signed caseback reveals the movement through a mineral glass etched with an image of the player. The Powermatic 80 caliber, an upgraded ETA 2824, operates at a frequency of 21,600 vibrations per hour and boasts an impressive 80-hour power reserve. Moreover, it incorporates a Nivachron anti-magnetic hairspring for heightened reliability.