The Silver Line opens Saturday and has already inspired screen cleaning cloths, hand sanitizer, and its very own song. What’s next? The Silver Line, balloon edition.

Washington Post reporter Julie Zauzmer, who works as a balloon artist on the side, built a Metro train car out of balloons to mark the opening of the new Metro line. Now it can be yours to take home!

Here’s how it works: Just like the real Silver Line, the balloon version took a lot more time and resources to construct than anticipated. How many balloons do you think went into this sculpture? Tweet your guess of the number of balloons to @PostLocal with the hashtag #balloonsilverline.

The person with the closest guess tweeted by 10 p.m. Saturday, will win the Balloon Silver Line. In case of a tie, the winner will be selected in a random drawing. The winner will be notified by noon Sunday.

The winner must pick up the balloon sculpture at The Washington Post, 1150 15th Street NW, Washington, D.C., by 5 p.m.  Monday, July 28. Click here for full contest rules. Prize subject to minor popping, shrinking and single-tracking.