UPDATE: A second trailer reveals more footage of the film including more shots of the mystery Harley. Watch it below.

Marvel has released a trailer for the next film in the Captain America franchise that may hold a surprise for Harley-Davidson fans. Harley-Davidson has been a long-time partner of Marvel, with several of its motorcycles getting featured in the comic book company’s films. True to form, the trailer for Captain America: Civil War includes snippets of a chase scene with a Harley. But what model is it?

The motorcycle scenes appear only briefly, starting just after the 1:00 mark with actor Sebastian Stan (or more likely, his stunt double) in the role of Bucky Barnes riding a Harley. At first glance, the motorcycle looks like a Street 750 but there are some clues that it may be something else.

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The physical size of the mystery bike looks similar to the Street, and we can see it has a similar rear fender, round instrument dial and twin rear shocks. However, as we can see from the image at the top of this post, the bike has LED taillights and red-coiled shocks with what looks like piggyback reservoirs, items that are not currently offered either on the stock Street or in Harley-Davidson’s parts catalog.

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We couldn’t get a clear shot from the overhead view but we can make out a few details. The fuel tank has a single filler cap on the right side of the tank which looks similar in shape and arrangement as the Street. Look closely at the front wheel however and we can see what looks like dual front brakes which are definitely not offered on the Street. Based on these clues, our best guess is the Civil War motorcycle may be a performance-oriented version of Street.

Of course, it’s possible that this motorcycle is just a one-off custom built for the film, but past history would suggest otherwise. In the previous Captain America film, 2014’s The Winter Soldier, Harley-Davidson debuted the Street while this year’s Avengers: Age of Ultron showcased the electric Livewire prototype. In both instances, the motorcycle was featured in a pivotal chase scene and were also shown in their film’s respective trailers (the Street actually appeared undisguised in the trailer a week before it’s official unveiling).

The two bikes also appeared in the films nearly unaltered, save for the removal of mirrors and license plate holders (these are also missing from the mystery bike in the trailer). In other words, if we can make out any details about a motorcycle in this trailer, it’s because Harley-Davidson wants people to see it. It’s likely then, that what we’re seeing is a future production model.

Captain America: Civil War is slated for a May 6 opening in North America (April 29 in the U.K.) so we expect Harley-Davidson to release information on this mystery bike before then.

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