The hand-held transmitter SHT-12 C1 enables remote control of functions of a radio module or receiver of the radio series SH-12.A blue LED indicates the transmission is in operation. It is not only sent radio signals, but also gives information about the quality of the radio communication and the transmitter power supply. The red LED displays, depending on the wiring on the radio receiver either the status of the receiver supply voltage or the input on the receiver confirmation. Via an integrated beeper is a confirmation of the receiver also signalled acoustically. The confirmation is deactivated, instead of each change of the key status is reported.The hand-held transmitter of the radio series SH-12 due to their special transmission properties Extremely low disturbance. With the lack of interference-resistant radio transmission with extremely short response times can range over 1000 m can be achieved. For strong narrow-band interference or the use of multiple parallel radio systems, t