The numbered buttons on your handset are pre-set cruise control speeds to use when you are using remote control mode. You can reprogram these for your own walking speeds as follows:
1. Use the speed up and slow down buttons to find your desired walking speed
2. Press and hold the button you want to program for three seconds: the trolley will stop
3. Release the button and the trolley will restart: your new speed is now stored.
The button speeds can be accidentally programmed to zero speed: don't worry, just follow the steps above and all will be well.