National Hockey League License AGS Pro dampening system keeps ball from bouncing Molded PVC ball Franklin Sports National Hockey League (NHL) AGS (Active Gravity System) Pro High Density Ball is designed for us in temperatures above 32 degrees Fahrenheit. The Active Gravity System is a patented design that uses a superior no-bounce technology to sustain a lower center of gravity in each ball. A proprietary micro-pellet dampening material suspended with a liquid keeps the ball from bouncing for better passing, shooting and control.