PROPEL X™ COVERSTOCKIntroducing Propel X reactive coverstock, the newest addition in Brunswick coverstock technology. Propel X features an enhanced pore structure to provide Xtra consistency from shot to shot and Xtra versatility on a wider variety of lane conditions.MACE™ COREMechanical Asymmetric Core Engineering. The MACE medium RG core has three major benefits, medium RG core system for a breakpoint further down lane, high RG differential to increase backend traction and high RG asymmetric differential to quicken the response time to friction.BALL MOTIONThe Wicked Siege combines the new Propel X coverstock and the MACE medium RG core to produce a ball motion that is clean through the front, consistent in the mid-lane with a quick response to friction on the backend. With its consistency from shot to shot and versatility across the lane, the Wicked Siege will be the fi rst ball out of your bag and a new benchmark ball for Brunswick on medium to oily lane conditions.REACTION SETUPThe Wicked Siege can be drilled using the standard drilling techniques developed for asymmetric bowling balls.LIGHTWEIGHT ENGINEERINGThe unique core shape of each Brunswick ball is used for weights from 14 to 16 pounds. This approach to lightweight ball engineering provides bowlers with consistent ball reaction characteristics across this weight range. The same drilling instructions can be used for 12- and 13-pound balls. This is because Brunswick uses a generic core shape with an RG differential that is close enough to the 14-16 pound shape.