The short answer
There is no Patek Philippe Reference 6002A. Patek has never catalogued a Sky Moon Tourbillon in stainless steel, and "A" is the company's own suffix for steel. The only genuine 6002 is the 6002G, a white gold, double-faced watch with 12 complications that Patek introduced in 2013 as the successor to the 5002. Any listing, auction ad, or social post offering a "replica 6002A" is working from a reference number the manufacture never assigned. That one detail tells you most of what you need to know about the seller.
Why the letter suffix matters
Patek's reference codes end in a material letter: J for yellow gold, R for rose gold, G for white gold, P for platinum, A for stainless steel. A Nautilus 5711/1A is steel. A 5711/1R is rose gold. So "6002A" reads as a steel Sky Moon Tourbillon, a watch that does not appear in any Patek catalogue, past or present.
What the real 6002G actually is
The 6002G carries a minute repeater with cathedral gongs, a tourbillon, a perpetual calendar, and a sky chart with sidereal time and moon phases, split across two dials. The case is hand-engraved, the dial is grand feu cloisonne enamel, and production numbers are tiny. Secondary market transactions run into seven figures in US dollars. That context sets the bar for anything marketed as a replica of it.
What a "6002A replica" gets wrong
- No working minute repeater. A cathedral gong repeater is the reason the real watch exists, and it is the one thing replicas cannot fake convincingly.
- The sky chart is a printed disc or a painted dial, not a rotating sidereal display.
- Engraving is laser cut or stamped. Hand engraving has undercutting and depth variation you can see under a loupe.
- The enamel is painted resin or a decal, not fired vitreous enamel.
- The reversible case is usually a decorative back, not a second functioning dial.
How I would check any listing
Start with the reference number. Look it up on Patek's own site or in a major auction house archive. If the number returns nothing, stop there.
Next, reverse image search the photos. Replica sellers reuse the same studio shots across dozens of storefronts, so a match usually means the images are borrowed.
Then ask for a movement photo. A legitimate seller will send one. A seller working with a generic automatic or quartz movement will stall, crop the image, or go quiet.
The legal side in one paragraph
Counterfeit watches are a trademark problem, not a victimless hobby. In the United States, trafficking in counterfeit goods is actionable under the Lanham Act and can be prosecuted criminally. US Customs and Border Protection seizes and destroys counterfeit shipments, and a buyer's name can end up in a seizure record. Beyond the legal risk there is no servicing path. Patek will not touch a counterfeit, and most independent watchmakers will not either, which means a dead movement is a dead watch.
What to do instead
If you want the look of a complicated, hand-finished dress watch, several independent makers build genuine pieces in that spirit for a fraction of seven figures. If you want a Sky Moon Tourbillon, that conversation happens at auction or through an authorized dealer. Either route gets you a watch someone will still service in ten years.