4KS is the most resistant system among mechanical locking systems. With the patented, springless curve technology, 4KS is suitable for the toughest conditions. The reversible key is convenient to insert and turns easily and silently in the cylinder. And of course, 4KS also has a feature unique to EVVA: The overlapping curve millings guarantee optimal security.
The benefits of 4KS at a glance
  • for locking systems with a highly complex structure
  • springless technology
  • modular version (SYMO)
  • in compact and modular version (SYMO)
  • Patent protection until 2035
Optimised key tip for easy insertion
Overlapping curve system
Additional coding
Made from high-quality nickel silver
Picking and scanning protection
The 4KS cylinder is equipped with several locking sliders. Thanks to the freely moving locking elements in the plug, it is virtually impossible to scan the cylinder in order to make a copy key. The springless function also protects against bumping.
Drilling protection
The hard metal control bars which also provide a body drilling protection in the 4KS cylinder offer effective protection against drilling..
Plug pulling protection
The hard metal control bars and the modular version (SYMO) offer effective protection against pulling and snapping attempts.
4KS-cylinder options
The 4KS options make it possible: External key override cylinder function; Classroom and SOS function; dust protection; free-wheel function; cogwheel cam and much more.
The Key
As a reversible key with unique rounded tip, the 4KS key is particularly easy to use. The high-quality nickel-silver alloy of the key, the anti-friction coating of all locking elements and the springless technology of the 4KS plug guarantee high wear resistance even under the toughest conditions. The special feature of the 4KS key, however, are the overlapping curve millings. It practically rules out key manipulation within the locking system. The additional coding also provides highest security.
The Cylinder
4KS is patented, springless and anything but conventional. In contrast to other locking systems, the locking elements in the 4KS cylinder are sliding along the curve millings on the key. No force is needed to insert the key due to lacking spring resistance. A total of 12 springless, solid locking pins are brought into specific positions via positive control of the 6 curves milings on the key and are scanned via 2 control bars. A locking bar in the plug controls the key’s additional coding. The 4KS key is scanned a total of four times and therefore offers the highest security.
The 4KS cylinder is produced in modular version (SYMO) and can there fore be adapted to the relevant door situation directly on-site. The 4KS cylinder can also be customized with specific functions on-site (e.g. external key override).