Zenith G.F.J. Calibre 135 in tantalum: a chronometer defined by material

Zenith's April 2026 G.F.J. in tantalum is a genuinely distinct material-led interpretation of the Calibre 135 family. Reference 98.1865.0135/21.C212 is limited to 20 pieces and has a 39.15mm case in dense, blue-grey tantalum.

The layered dial combines a polished onyx centre, grey mother-of-pearl small-seconds counter, brick-pattern guilloché outer sector and diamond hour markers. Calibre 135 is manually wound, COSC-certified, runs at 2.5 Hz and offers 72 hours of reserve.

The useful design story is whether materially expensive complications of manufacture add visible character, rather than simply cost. Zenith describes tantalum's machining difficulty; this remains a sourced manufacturer claim, not an independently observed production process.