For status display of window handle positions: open = red, closed = green, tilted = yellow. Direct onsite operation possible for switching / dimming an electrical device depending on the flush-mounted insert. 4 individual LED display channels. Up to 8 WaveLine transmitters can be taught-in on each LED display channel. Up to 8 WaveLine transmitters can be taught-in on onsite operation. After a power cut all LED-Display channels light in red. The cyclic telegram repeat of the WaveLINE window position sensor 6720-xxx sensor automatically updates the window open state. Status display for depleted WaveLINE transmitter battery. Status display for faulty transmission link and defective WaveLINE transmitter. User-friendly start-up without PC / software. Printed labelling sheet with 8 different inlay sheets. For WaveLINE window position sensor 6720-6x. For WaveLINE 6721-xx universal signalling unit. For Busch-Watchdog 220 WaveLINE 6747 AGM. For Busch-Universal relay switch insert 6404 U. For universal dimmer switch insert 6595 U. ./. Free-field range: approx. 100 m. Send/receive frequency: 868 MHz.