JGR1038 Features: * Stacker block kit with bow and stern lines * Transform your StaxPro into a two boat carrier for whitewater, recreational and high end composite boats * Two 8"" foam blocks protect kayak (even high end composite boats) by cushioning the kayak so that it does not rest directly on the cross bar * Blocks allow boat to stay in place and not slip during loading and strap down * Blocks conform to round, square and factory oval cross rails * Two 12" tie down straps and bow and stern lines secure kayak to foam blocks * Made in USA Warranty: * Manufacturer provides one year warranty