Amazon is preparing to launch a secret product later this month.

In an email sent to Amazon Flex delivery drivers, obtained by GeekWire, the tech giant is gearing up for a “secret new product launch” on July 31 from midnight until 2 a.m.

“At 12:01 a.m. on Sunday, July 31st, Amazon customers will be able to get their hands on a brand new product,” the email reads. “We are not able to share with you what this product is until the launch time, but you could be one of the first in the world to see it by delivering during a block created just for this release!”

I just got an email from Amazon asking if I'd like to deliver a new 'secret product' on the 31st… Ooooo! — Erika (@Sweetweets2504) July 21, 2016

It’s certainly a peculiar time frame for a product launch. Amazon Flex drivers typically work until 12:30 a.m. at the latest. The Amazon Flex program, first reported by GeekWire in August, is an Uber-style delivery network that enables private drivers who use their own vehicles to deliver packages. It started in Seattle this past fall and is now live in nearly 30 cities.

As to what exactly the “secret” product is, some drivers speculate that it could be Pokemon Go Plus, the highly-anticipated wearable device that lets Pokemon Go gamers play the popular game without taking out their smartphone.

Other say it could be related to Harry Potter, or potentially the Samsung Note 7, which will be officially unveiled next month.

Or, it could be a new device from Amazon — maybe a new Kindle Fire tablet or something related to the Amazon Echo line.

Amazon did a similar midnight delivery promotion this past November, when it offered the new Call of Duty game to Prime members. It’s unclear if the product launch on July 31 is only for Prime members, or anyone.

The secret product launch is also reminiscent of how Amazon offers flash deals via its Treasure Truck, which drives around Seattle with heavily-discounted items that people purchase via Amazon’s mobile app.

We’ve contacted Amazon about the new product and will update this story when we hear back.