These magnetic door retainers are intended to hold doors open under normal conditions to ensure the smooth flow of internal traffic. However, if a fire breaks out and the doors need to be closed to prevent the spread of smoke and fire in the building, these magnets can be unlocked via the fire alarm. By switching off the power or pressing the unlock button, the magnet is deactivated. Thanks to the modular structure, a single set can be used for all door configurations. So short and long versions for wall or floor mounting in one model. The tube can also be cut to size to obtain the desired mounting distance.