Laptop lock with key 221 refers to a specific key used to unlock a particular laptop cable lock, likely a Kensington Security Slot lock or a similar type that uses a mechanical key for the physical security of a laptop. The key itself would be a uniquely cut metal key that fits into the lock mechanism, while the number "221" is the specific identifier for that unique key and the lock it operates, allowing you to secure and detach the lock from the laptop's security slot.