For under $20, the Stacker Block Kit allows you to turn your $114.95 StaxPro into a 2 boat carrier. This is simply a value that is unmatched in the market. Buy additional kits for additional boats. The foam Stacker Block holds the kayak in place during loading and cushions the kayak during transport so that it does not rest on the cross bar.

Features:
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 or factory oval cross bars
Two 12' tie down straps secure kayak to foam blocks

Specifications:
Capacity: 70 to 80 lb kayak
Dimensions: 4" x 8" EVA closed cell foam blocks