Locks refer to the closure of the equipment, including locks, keys and accessories, generally interpreted as "must use the key to release the sealer." Now, in addition to the key to open the lock, but also with optical, electrical, magnetic, acoustic and fingerprint instructions to open. Locks are not only protective products, but also have the functions of "management" and "decoration". There is also a kind of etiquette in international communication, with the token of "key" as a token of friendship.