Lock system

A lock system comprising;

• at least one flat safety key (1), two lock cylinders (5, 6), each of which have at least one rotor (9, 10) with a key channel (7, 8) for introduction of said at least one flat safety key (1), said at least one rotor of a first lock cylinder of said two lock cylinders rotated 180.degree. about an axis of rotation with respect to a first corresponding cylinder housing (11) of said first lock cylinder in comparison to said at least one rotor within a second corresponding cylinder housing (12) of a second lock cylinder of said two lock cylinders when said at least one rotor (9) of said first lock cylinder and said at least one rotor (10) of said second lock cylinder are respectively fixed by lock rows in said first corresponding cylinder housing and said second corresponding cylinder housing,
• the lock rows being aligned and the corresponding rotor turnable within the cylinder thereon when the key is introduced into the key channel,
• said at least one flat safety key (1) being a non-reversible key having a plurality of bores with one lock code for alignment with the lock rows of said first lock cylinder or with the lock rows of said second lock cylinder,
• or having a plurality of bores with two lock codes, one code for alignment with the lock rows of said first lock cylinder and the other code for alignment with the lock rows of said second lock cylinder.