Add some wake building potential to your Mastercraft boat when you install the Mastercraft Rear Gravity Games Sac. This durable PVC ballast bag is made from the toughest of tough PVC and designed with welded seams for extra strength. When filled with water this Fly High sac gives you an additional 565 lbs of water weight for amped up wake surfing. Because this versatile little bag can be installed in multiple configurations, this kit does not include all the fittings or hoses you will need so plan accordingly when you order. Fly High Pro X Series ballast bags are some of the most durable and well-constructed bags you will find, giving you years of amazing wake.