The MPG169 Stacker Kit can be added to any stacker style carrier system to hold the kayak in place during loading and cushion the kayak during transport. A great way to protect the boat finish and avoid abrasions from the load bars. Fits round, square or factory oval load bars. One Year Limited Warranty. Features: 8" long EVA foam blocks with a top radius to fit most kayaks (on-side) 11' cam buckle load straps to secure the boat Safety tie-downs to fully ensure a safe installation Universal cut-out to fit most round, square and factory oval load bars One Year Limited Warranty Specifications: Weight: 1.5 lb Length: 8" (per block) Width: 4" (per block) Height: 3.25" (per block) Load capacity: 55 lb What s In The Box: (2) 8" Long EVA Foam Blocks (2) 11' Straps (2) Bow and Stern Lines (1) Instruction Manual