Unique 3D printed Mobius Strip Keyring.
A mobius strip is a surface with only one side: If its full length is traced by your finger, your finger returns to its starting point having traversed both sides of the keyring without ever crossing an edge.
The key ring is made from bronze infused steel, and is 32mm in diameter. Shown in the photos with a standard UK Yale key (not supplied!).
3D printed to order, in a choice of steel finishes: the photographs show polished bronzed-silver steel.