These pieces are minted NFTs on Ethereum, but they also come with physical versions.
The physical works have a read-only radio tag screwed into them. You can scan it with most modern phones.
The tag contains 1.) a uniquely generated identification number that conforms to the UUID standard, and 2.) a random string of characters (a salt or nonce).
When you run them together through a standard SHA-3 hash function, you'll get a new, unique string of characters—a checksum. The irreversible checksum is in the NFT metadata.
To verify that you are holding the physical thing connected to the NFT, scan the tag, hash the UUID and the salt, and then check that the resulting string matches what's in the NFT's metadata.
Listings are on OpenSea. All proceeds go to an Ethereum wallet that's been donated to BUILD, a non-profit entrepreneurship program for underserved high school students.