The Zoo Hardware Vier Precision Euro Profile Offset Cylinder & Turn is designed for enhanced security and durability. It features an anti-drill cylinder, anti-pick cylinder, and a break-off system for added protection. This cylinder is certified to BS EN 1303 and BS EN 1634-1 standards, making it suitable for fire doors (30-60 minutes). It comes with 3 specially manufactured, hardwearing silver nickel keys as standard. Keyed Alike, Keyed To Differ, and Master Keyed Systems are available. Please note that Keyed Alike and Master Keyed options are made to order and cannot be cancelled or returned. It is recommended to measure your existing cylinder before ordering. Master keys are sold separately.