If no hermetic separation required, the doors can also be supplied with a slightly modified door leaf. Due to the elimination of the hermetic closed position, optical changes occur to the lower leaf guides and the path of the door. Otherwise, the visible similarity to the K1 / K2 series remains, enabling homogenous designs to be implemented.
The “na“ model of the K system is based upon the one-winged (K1-A ST) and two-winged (K2-A ST) door models and is not hermetically sealing.