1. A device that, when installed on a firearm, is designed to prevent the firearm from being operated without first deactivating the device;
2. A device incorporated into the design of the firearm that is designed to prevent the operation of the firearm by anyone not having access to the device; or
3. A safe, gun safe, gun case, lock box, or other device that is designed to be or can be used to store a firearm and that is designed to be unlocked only by means of a key, a combination, or other similar means.
Zip ties, rope, and string do not meet this definition.
[18 U.S.C. 921(a) (34)]