Google will let companies ship their data to its cloud through a new piece of hardware that’s designed to speed up cloud migrations, with the help of FedEx. The company’s new Transfer Appliance will let customers load up a secure machine with data stored in a private data center and then mail it to Google Cloud Platform.

While essentially sticking a box of hard drives on a delivery truck may seem like an awfully antiquated way of transferring data, it can actually be faster than trying to transfer the same information over the internet. That’s important for the enterprise customers with large volumes of information that Google Cloud is trying to court.

Over the course of Google’s work with its cloud customers, the company found that businesses had many petabytes of data to transfer, but doing so over a traditional network could take years. Using the Transfer Appliance, companies can move that same data in a matter of weeks.

This is also a move to compete with the Snowball set of shippable storage appliances from Amazon Web Services. AWS introduced the first Snowball, a ruggedized 50TB storage appliance that customers could use to ship data to its cloud, in 2015. That lineup has since expanded to an 80TB Snowball and a 100TB Snowball Edge that also offers compute capacity. For companies with a literal truckload of data, AWS’ Snowmobile will let them transfer 100PB at a time from their data centers to the cloud, using a big rig stuffed with storage.

Operations engineers can mount Transfer Appliances inside data centers on a standard 19-inch-wide rack, alongside other servers. Google offers two sizes: a 100TB version that takes up a single rack unit and a 480TB version that occupies four rack units. With compression, users should be able to fit up to 200TB on the smaller unit and 1PB on the larger one.

The smaller model costs $300, plus shipping, which Google expects will be around $500 round trip. Getting a larger model will cost $1800, plus about $900 in shipping. They’ll only be available in the U.S. at first.

Dave Nettleton, Google’s group product manager for its Cloud Storage products, sees a couple of common uses for the appliances. Companies can use them for a single migration from an on-premises data center into the public cloud, or for recurring batch uploads of locally processed data that they then want to make available for analysis in the cloud.

It’s hard to say exactly how long it will take to fill each of the appliances, since that depends a lot on the configuration of the data center in which they’re mounted.

Hard drives within the transfer appliance are set up to withstand multiple failures, so businesses shouldn’t lose data if one or two drives go bad. (For the storage nerds out there, they’re running in a RAID 6 configuration.)

Businesses concerned about the security of their data should know that information loaded onto a Transfer Appliance is encrypted using keys that they control.

“All of the data that lands on the appliance is encrypted as part of the ingest process, using AES-256 encryption,” Nettleton said. “Keys are never sent or stored on the appliance, so they’re all handled outside the appliance. The raw data is then stored encrypted on the appliance, and the data is only ever decrypted by the customer once it’s uploaded to [Google Cloud Storage] on the other side, so we never see the keys.”

Once an appliance returns to Google, the company also erases and zeroes out all of the data it contains before shipping it to another customer.