Locking system DU with 3D key sections

Contract business

“DU” means “Double Undercut”, which directly points to the most important feature against unauthorised copying of keys: the double undercut on the lateral key sections. The resulting three-dimensional groove cannot be copied by conventional copying devices which exclusively copy in two dimensions.

This locking system, which is patent-protected until 2031, can be adapted individually and gradually to the most varying requirements. Depending on its features, it even complies with the most stringent requirements in accordance with DIN 18252, DIN EN 1303 and the VdS guidelines.

Especially designed for upscale industrial buildings, this system satisfies the complex requirements of a building on organisation, convenience, economic efficiency and of course security.

Two optional swivelling levers arranged on one side and acting on a locking bar serve as a highly-effective locking element which performs a double security scan over the length of the key section.

System description

  • DIN 18252/EN 1303 compliant
  • In accordance with the VdS guidelines 2156 and 2386 for single locks and master key systems
  • 5/6 spring-loaded main locking elements on each cylinder side, working gradually and vertically, plus up to 5 additional control and locking elements which scan the key section laterally, increase locking security.
  • At least one driver pin and all key pins are made of hardened steel (as an additional safety feature against opening by drilling)

  • Anti-scanning feature due to specially shaped driver pins acting as a protection against picking tools.
  • A guiding groove along the entire cylinder plug ensures the positive transfer of the key torque.
  • Stable nickel-silver key in accordance with DIN requirements for customary
    handle sets with cylinder cover
  • Profile with a high number of variants, protected by law
  • Manufacturer profile for use in master key and grand master key systems
  • Also available with British and Scandinavian profiles

Spring-loaded swivelling lever

No slippage because of safe barrier

In the locking cylinder, two swivelling levers arranged on one side perform a double security scan over the length of the key section and serve as an effective element against forceful picking.


Increased safety made visible

On the opposite side of the swivelling levers, up to five horizontally-supported control pins in the cylinder plug, which can be inserted as required, serve as an additional safety feature.

Anti-drilling, anti-pulling protection

Additional locking function

The cylinder is additionally equipped with a spring-loaded locking element in the case made of hardened special steel. This locking element performs a contour-controlled security scan of the key.

Can be combined with electronic locking systems

CES’s mechanical locking systems can be combined with their electronic locking systems. The combination of both systems has often proven to be useful in practical applications.

The combined key allows you to operate the mechanical cylinders and the electronic locking devices at the doors.

The CES OMEGA FLEX electronic locking system