The US-based American rocker arm is currently the most widely used electronically controlled camera rocker arm in the world. The American rocker arm is currently the most widely used electronically controlled camera rocker arm in the world. The most widely used electronically controlled camera rocker arm in the United States. The American rocker arm is the most widely used electronically controlled camera rocker arm in the world. The US Jimmy rocker arm is currently the most widely used type in the world. Electronically controlled camera rocker arm US Jimmy rocker arm is currently the most widely used electronically controlled camera rocker arm in the world.