At a particular price level, when aggregate demand for final goods equals aggregate supply of final goods, the product market reaches to its _________.

Equilibrium level

When, at a particular price level, aggregate demand for final goods equals aggregate supply of final goods, the final goods or product market reaches its equilibrium.  This means that there is no excess supply or excess demand for goods and services, and the economy is operating at its full potential.

Aggregate demand for final goods consists of ex ante consumption, ex ante investment, government spending etc.