Can ab king pro really help in getting a flat stomach ?

Don't buy anything: Even the most toned abdominal muscles will not reveal the abdomen you want if they are buried under a beer gut. Decreasing body fat is a key component of washboard abs. That said, anything that strengthens your core (sit ups, crunches, leg lifts, torsion, etc ) all play a role in building those muscles. Eat healthy and do lots of sit-ups.