To Earth your Inverter. Drive the earth stake into the ground and run a 16mm cable from the Inverter Earth to the earth clamp, attached to the earth stake. Earth is an important part of your electrical system, you need to have an earth for safety. In audio equipment you will usually encounter problems if there is no earth stake.
Electrolyte copper bond earth rod. Non expandable.
Brass. Rod to lug earth clamp.