Deaver - 2" Lift Medium Duty "Shackle Required" (U748) - Toyota Tundra (2007-2022)Hardware and bushing kits are not included with leaf packs unless you choose the option. Deaver Progressive Series springs are high quality 9 leaf and 10 leaf units fabricated with high grade 5160 American Made steel. A higher leaf count spring allows the use of thinner leaf material that yields a more flexible progressive leaf stack, or pyramid, producing a much smoother spring rate curve throughout the complete suspension cycle. The even, linear