Cal. 6497 is a large pocket watch movement produced by Unitas and ETA since 1950 and continuing until the present day.

The Cal. 6497 family is a Lépine pocket watch calibre and thus has the sub seconds dial at 9 00, in line with the crown and winding stem, but is closely related to Cal. 6498, the hunter version. It is a large movement, measuring 16.5 ligne (36.6 mm) in diameter but is only 4.5 mm thick thanks to a compact manual winding design. Modern 6497's are fully jeweled (17 jewels) though some have only 15. Most 6497's operate at 18,000 A/h, though some '6497-2 versions, like Panerai's “OP” movements, tick at 21,600 A/h. Power reserve for modern versions is 46 hours, though Panerai boasts 56 hours.

Cal. 6503 is identical to Cal. 6497 but adds a date wheel. It is 5.0 mm thick but otherwise shares the same specifications. Cal. 6503 was not updated to “-1” or “-2” specs and is no longer manufactured.

Although developed for pocket watches and far too large for the small wrist watches that were popular in the 1950's, the advent of large sports watches has made Cal. 6497 popular on the wrist. In particular, Panerai brought the movement to popular acclaim with their Radiomir, Luminor, and Luminor Marina models. Other makers who use this calibre include Alpina, Anonimo, Chronoswiss, Dornblüth, Eberhard, Guinand, Omega, Maurice Lacroix, Rado, Tissot, and U-Boat.

Cal. 6497 is also the most-widely used teaching movement in watchmaking schools, making it very well-understood by watchmakers.

• Unitas 6497 (1950) - 18,000 A/h
  • ETA 6503 - Date version of Cal. 6497
  • ETA 6497-1 (1967) - Updated ETA version with pallet lever bridge instead of cock and Etachron regulator
  • ETA 6497-2 - Elaboré version with Incabloc shock protection and basic decoration; some operate at 21,600 A/h
• ETA 6498 - Savonnette version
  • ETA 6498-1 (1967) - Updated ETA version with pallet lever bridge instead of cock and Etachron regulator
  • ETA 6498-2 - Elaboré version with Incabloc shock protection and basic decoration; some operate at 21,600 A/h

• 6497
  • Omega 960 - Triovis regulator
• 6497-1
  • Alpina AL-435 - in-house finishing on ETA/Unitas 6497/8
  • Alpina AL-650 - in-house construction based on ETA/Unitas 6497/8
  • Chronoswiss C692
  • Dornblüth 99.2
  • Maurice Lacroix ML-16 - Skeletonized
  • Maurice Lacroix ML-1 - Double retrograde calendar and second time zone
  • Maurice Lacroix ML-100 - Double retrograde calendar and second time zone, power reserve indicator
  • Panerai OP XXIX
• 6497-2, 21,600 A/h
  • Panerai OP I
  • Panerai OP II
  • Panerai OP X
  • Panerai OP XI - With swan neck regulator and new bridges
  • Rado RHW1 - Aluminum construction

• ETA 6498