Featuring our new Vanguard Core Technology, a HOLE new concept More Continuation, Less Deflection, and Better Pin Carry it is truly a WEAPON OF MASS BIAS. WMB offers a 75% Stronger Mass Bias and a 20% Faster Spin Time than our previous core designs, and is surrounded by an all new Versatile Particle Cover. It's SO dramatic, you can SEE and HEAR the difference!Product Type Bowling Balls