The Zen utilizes a pearl version of the S77 Response cover combined with a gigantic symmetric core. The S77 Response Pearl Cover provides the strongest reaction we have ever put in an 800 Series ball. The Zen will be a great ball to open your angles up with on medium to heavy patterns. The Meditate Core is the biggest core we ever put into a bowling ball. A bigger core means more hitting power combined with a more consistent shape on the lanes. The Zen pushes the limits of core dynamics15 LBS.