Rolex Oyster Perpetual 6551

The Rolex Oyster Perpetual ref. 6551 is a notable and rare vintage model introduced in the mid-1950s, historically regarded as a transitional reference that shares close ties with the early Rolex Milgauss line. Its stainless steel case measures 38mm in diameter—larger than the standard Oyster Perpetual of the era—and often included a thick case profile to house the anti-magnetic protection system. The watch was equipped with the Rolex Caliber 1030, a bi-directional self-winding movement with a 42-hour power reserve, shielded by a soft iron inner cage that enhanced resistance to magnetic fields. Dial configurations varied, with some featuring luminous markers and hands, as well as honeycomb textures and lightning bolt seconds hands—traits now closely associated with the Milgauss ref. 6541. The 6551 included a screw-down crown and caseback, preserving water resistance despite the inner shielding. Lug-to-lug measurement is approximately 48mm with a lug width of 20mm, emphasizing its sporty dimensions. Originally fitted with Oyster bracelets or leather straps, the 6551 is one of the most collectible and elusive mid-century Rolex references, often seen as a prototype or pre-Milgauss release. Its rarity, technical innovation, and crossover appeal between the Oyster Perpetual and professional tool-watch families make it exceptionally desirable among vintage Rolex collectors.