What a Fake Type XXI 3817 Is

The Breguet Type XXI 3817 is a 42 mm flyback pilot chronograph sold in steel and titanium, with a slate dial, a date aperture, and an automatic movement under a sapphire caseback. A fake Type XXI 3817 is any watch that copies that design without coming from Breguet. The copies fall into three grades: a quartz-driven lookalike, a mid-grade automatic with a stock movement, and a high-grade replica that mirrors the case dimensions and the dial layout.

Spotting one comes down to four checkpoints: the caseback engraving, the pusher and crown feel, the dial printing under magnification, and the finish of the movement behind the display back. The steps below walk through each check in order.

Prerequisites

  • A 10x loupe or a macro lens
  • A digital scale that reads to 0.1 g
  • Digital calipers
  • Reference photos of a confirmed 3817 (front, back, movement)
  • A soft cloth and clean gloves

How to Check a Type XXI 3817

  1. Weigh the watch head on the scale and compare the number with published specs for the steel or titanium version. Titanium reads lighter than steel, and a plated brass case reads far lighter than either.
  2. Turn the watch over and study the caseback engraving with the loupe. Look at the crispness of the reference number, the serial, and the Type XXI text. Laser etching on a fake cuts shallow and uneven.
  3. Run a fingernail across the engraving. Genuine engraving sits in a clean recess. A printed or shallow-etched fake feels flat.
  4. Check the serial against the reference table for the 3817 series and note any mismatch between the caseback number and the number stamped on the movement bridge.
  5. Tilt the crystal under a lamp. Breguet coats both faces, so the dial stays readable at sharp angles with almost no colored flare. A single-side coated fake shows a blue or purple wash.
  6. Inspect the dial printing at 10x. Confirm the Breguet signature, the Swiss Made mark at 6 o'clock, and the numerals. Look for filled counters, uneven serifs, and ink that sits above the surface.
  7. Check the lume plots with a UV light. Genuine application is even and level. A fake often shows bubbles, drips, or a color mismatch between the hands and the hour markers.
  8. Wind the crown and feel for grit or backlash. Press each pusher. A genuine flyback module returns a firm, short click with no side play.
  9. Start the chronograph, let it run for 60 seconds, then press the flyback pusher without stopping the movement. The hand should snap to zero and restart in one motion. A fake with a standard chronograph module will stop or stutter.
  10. Let the chronograph run for 30 minutes and check that the minute totalizer advances in step with the central hand.
  11. Set the date and watch the change. It should flip clean and land centered in the aperture. A fake often half-flips or shows the next number at the edge.
  12. Measure the case across the bezel and between the lugs with calipers. Compare the numbers with the published dimensions of the 3817, including the lug width.
  13. Look through the sapphire back at the rotor, bridges, and screws. Check for Geneva stripes, polished bevels, blued screws, and a signed rotor. A stock movement with no decoration and a blank rotor is a clear tell.
  14. Examine the strap or bracelet hardware. Stitching should be even and tight, the buckle should carry a sharp hallmark, and the end links should meet the lugs with no gap.

Replica Grades and What They Get Wrong

  • Low grade: quartz, printed caseback, mineral glass, plated case that reads light on the scale.
  • Mid grade: automatic stock movement, correct case size, weak dial printing, and a flat chronograph function.
  • High grade: close case dimensions and a decorated movement, but a thicker caseback and a pusher feel that does not match the flyback action.

Limits of a Visual Check

Photographs and a loupe get you far, but they cannot confirm a movement. Any Type XXI 3817 sold without service history, box, and papers should go to a watchmaker with a timing machine before money changes hands. Ask for a movement photo, an angled caseback photo, and a weight reading in grams before you agree to a deal.