Reference 3448 is without a doubt a milestone in Patek Philippe’s production. The case as well is remarkable, and a true break with what seen until that time at Patek Philippe. The curvy lines of previous perpetual calendar cases (such as ref. 1518, 1526, 2499, 2497…) are completely abandoned in favor of a futuristic design defined by sharp edges and straight lines, adapting to a fashion which was budding in the late 1950s and fully bloomed throughout the 1960s and 1970s. The large sloped bezel works in conjunction with the clean dial and amplifies the already generous 37mm dimensions of the watch.

The model was introduced in 1962 and four series are recognized for this model, with a total output estimated at 586 examples:
- The first series features small calendar ring, indexes closer to the center of the dial and engraved/enamelled minute divisions
- The second series introduces beady minute divisions
- The third series maintains the beady divisions but introduces the large numerals for the date rings and indexes closer to the outer edge of the dial
-The fourth series - exemplified by the present timepiece - features printed minuted divisions.

The connoisseur will immediately notice the superb condition of the piece, its case covered with a strong layer of oxidation indicating years spent in a safety deposit box. Once the watch is turned, not the usual one or two, but astoundingly four perfectly crisp hallmarks - including the one on the caseback, an obviously very sensitive location - greet and delight the beholder. Finally, its appeal and collectability are boosted to a superior level by the presence of the Gübelin signature, one of the most respected watch retailers in Switzerland. Co-signed pieces are an extremely rare find and are equally coveted by collectors; in conjunction with the superb condition, the co-signature makes this example a “trophy watch” which will be treasure and delight of its new owner for years to come.