If, for example, a new door is installed due to renovation, then only the centerpiece needs to be replaced, as the cylinder length is different. With the new cylinder housing for fire and smoke protection doors, Uhlmann & Zacher offers a special solution for the use of electronic knob cylinders in doors up to the fire resistance class ‘fireproof’ (T90). In combination with the appropriate knob module and the mechanical knob, the respective certified fire protection product is assembled by simply fitting together the components. This solution is also available in combination with the knob module for outdoors.