This easy-to-install kit allows you to transport your stand-up paddleboard or sit-on-top kayak. Compatible with factory racks, after-market racks, and vehicles without racks, the SUP Carrier Kit fits all cars. Includes: two 31" SUP/SOT blocks with non-skid base, two 23" stacker blocks, two 9' block straps and two 15' center straps with cam buckle. Carries 1 or 2 SUP/SOTs. Wt: 2 lbs 3 oz. Stacker blocks allow for secure stacking of SUP/SOT’S on SUP carts or to add more capacity to the SUP Carrier Kit. Sold in packaged pairs.