Security fittings with core draft protection. Good locks go in combination with approved (SKG) safety fittings, without this safety fitting even the best locks are easy to open. Burglars today have a so-called "cylinder puller" with which they can remove your cylinder from your security fittings within seconds and then easily open your door.
Special security fittings with core draft protection have now been developed for this. Your cylinder is completely protected on the outside by a safety ring, so that this technique can no longer be used. Security fittings with core pull protection are available in many types, brands and sizes.