The AMB-IMMORTAL is the latest adaptation of our highly successful Anti-Mass Bias core design. Unlike other balls which use dense materials to create a mass bias, the AMB design utilizes an extremely light cap opposite the desired mass bias location. This AMB flip cap creates a negative mass bias on the side with the cap and also creates a positive mass bias at the desired location. This allows the bowler to drill the ball in just about any possible manner, without affecting the core shape or dynamics.
The AMB-IMMORTAL core has a heavy cap added to the bottom of the core. This allows the density of the top cap to be increased significantly. The result is a core that produces an extreme flare potential with it's 0.078" differential (This ball was grandfathered in before the USBC changes and is currently higher than any new ball can be produced - BUT it is legal for use in all USBC competition because of when it was approved).