Roto Grip Bowling Balls. As the weak are eliminated, an EPIC BATTLEtm rages on! Roto Grip has forged the most effective weapon for the battlefield and puts it in the palm of your hand.Armoring the EPIC BATTLEtm is the new Ultimate Visiontm solid particle coverstock. The unique blend of a super strong base reactive material in combination with a light particle load gives you traction in the heaviest of oils.At the heart of the Battle is the new Maximus IItm weight block. This low RG 2.48 High Differential .050 core creates a Mass Bias Differential of .026 that generates an earlier move in the lane, then delivers a bone crushing backend reaction.