One item of jewellery popular with the Romans also served a practical purpose. This was the key ring, a combination ring and small key. Thus, a property owner or individual responsible for a storehouse or treasure room could wear the key and avoid losing it. The togas worn by many Romans had no pockets, so the only options for keeping small objects from getting lost were to keep them in a purse or wear them on one's person.
Two such key rings are illustrated on this page. Most Roman locks were what are called warded locks, meaning that they had metal wards or fingers within the lock that must exactly match the cut out areas of the key. The key was inserted into the lock and, if the key could be turned without some portion of it coming up against the wards, it would make contact with the lock's bolt and move it to unlock the lock. The shape of the key rings on this page indicates that the locks had fairly simple wards. Often, very intricate keys are found that fit a lock with very convoluted wards. This was usually the case with larger keys that were not part of a key ring.
The image at left is another view of the key ring at right. In this image we can see the hole in the end of the key which fits over a pin inside the lock used to line the key up properly with the wards. Not all keys and key rings had this feature, which became common in keys from a much later era. It just goes to show that some locksmiths in Roman times paid meticulous attention to detail.