Reversible flat key security cylinder providing optimal protection, thanks to its specific technical characteristics: - 17 active and passive pins in stainless steel - Hardened steel anti-drill pins, positioned vertically and staggered - 2 horizontally positioned pins preventing removal of the barrel - 5 nickel silver keys and card for duplication on sealed envelope - Stainless steel U element to prevent extraction of element in cases of damage due to attempted break in - Steel anti-pull cam.