All Vspeak Variometer use the existing telemetry system of modern radio controls.
The values measured by the vario can so be displayed on the radio or if applicable by voice output (+ Vario tone).
Remote control transmitters that are not equipped from the factory with a voice output can be retrofitted with the appropriate VSpeak speech module (which not only can speak optimal the data of VSpeak Vario's, also the data of other sensors). The speech module generates according to rising/falling a proportional Vario tone. At the VSpeak speech module a number of settings for the Vario tone can be made.
In addition to the height measurement, the vario also has a 3-axis accelerometer and a single cell monitoring. For the single cell monitoring there are Balancer adapter cables available under accessories.
German Forums on topic: VSpeak-Vario