Hunter GSP9720JLR Operation Instructions Manual page 36

Follow the on-screen prompts.
Position the valve stem at 12 o'clock, and then press "Enter Valve Stem."
After measuring rim runout, you will be prompted to loosen the wheel and re-clamp at
one half turn (approximately 180 degrees) from the current position.
Press "Start" when ready to take readings.
Once more, position the valve stem at 12 o'clock, and then press "Enter Valve Stem."
If the rim is centered properly, the following screen will appear briefly.
28 x Balancing Procedures
GSP9720JLR Wheel Balancer Operation Instructions