Since it is designed specifically for the NV350 caravan, it does not require any processing. (We recommend installing it at a specialist shop) The blocks are made of solid steel with a width of 2.3 inches (58 mm) and are resistant to breaking. U-bolt diameter is 0.4 inch (11 mm) thick and durable design. The mounting nut uses nylon nuts. Available in 4 different heights: 1.0 x 1.5 x 2.6 inches (25 x 38 x 50 x 65 mm). Kit Contents: Blocks x 2 pieces. U-bolts x 4. Nylon nuts. Comes with a strength certificate Compatible models: NV350 caravan. (Can be installed on all standard, wide, and super long vehicles) Compatible Model: E26 series Compatible years: June 2012 and up. Specifications: 2WD/4WD