Is your best Rolex replica watches gaining or losing value? The color of its bezel — the ring around the watch face — could be crucial.

The Bloomberg Subdial Watch Index shows two UK 1:1 Rolex fake watches are diverging in price on the secondary market, even though their only difference is the color scheme.

Prices for the most recent version of the high quality Rolex GMT Master II replica watches with a red and blue ceramic bezel, nicknamed the ‘Pepsi,’ rose 4.1% to about $21,000 over the past year, according to data from Subdial, a UK-based watch trading platform. At the same time, prices for what is known as the ‘Batman’ — essentially the same watch but with a black and blue bezel — declined 10.1% to about $16,000.

Both Swiss movements Rolex copy watches sell for the same price at retail — about $10,700 — on the same steel Rolex Oyster bracelet.

The divergence shows how a model’s desirability and perceived scarcity can affect prices. Dealers, collectors and watch industry media have speculated that the cheap fake Rolex Pepsi GMT watches could be discontinued this year amid talk of production challenges in making the red and blue bezel. It wasn’t and the model continues to be in the Rolex catalog.

With more than 10 billion Swiss francs ($11.1 billion) in annual estimated sales, Geneva-based Rolex SA is the biggest Swiss watch brand, controlling about a third of the overall market for premium Swiss watches, according to estimates by banks including RBC and Morgan Stanley. Rolex doesn’t disclose production figures for individual online China Rolex replica watches or overall. Analysts estimate the brand makes about 1.2 million watches per year in total.

Rolex is building a new production facility in the Swiss canton of Fribourg scheduled to open in 2029 that will add capacity to its existing four domestic production facilities in Geneva and Biel.

The Pepsi, which was the original bezel color when the GMT was first introduced in the 1950s, remains one of the most difficult Swiss wholesale fake Rolex watches to buy at retail from an authorized dealer. As with the Daytona chronograph, demand far outstrips supply, and clients can wait months or years before getting the call. Rolex introduced the Batman GMT in 2013.

The Pepsi’s 4.1% gain in a year contrasts with a 5.7% loss for an index of top Rolex super clone watches prices compiled by Subdial.

The Bloomberg Subdial Watch Index, which tracks prices for the 50 most traded Swiss made Rolex copy watches models by value on the secondary market, has fallen 8.7% in a year. The index was virtually unchanged in May.