To use THE HAWK, simply put your golf ball through the center hole and spin the ball around in all directions.
If the ball is out-of-round, you will feel it hang as you spin it. It might even hang tight enough to stick inside the hole.
If the ball is round, it will freely pass through THE HAWK and will not catch when spun around in the hole.
THE HAWK is precision machined to exact PGA specifications, so if your ball doesn't fit through the hole at all then it's too large for regulation play.
In our testing, we found that approximately 30% of brand new balls are not perfectly round even though they are within PGA specifications for size and weight.
In the video below, you can see that the first ball hangs up when passed through THE HAWK. This ball is out-of-round. The second ball passes freely through, and is therefore perfectly round.