These are the strongest and most complete leveling kits for the Frontier on the market today. These kits are built to last with machined billet 6061-t6 aluminum and grade 8 hardware; we guarantee the spacers for as long as you own your Frontier or Xterra. We recommend only the 2" for the 4wd (unless using the PRG UPPER CONTROL ARMS, then you can use 2" or 3" spacers) but either for a 2wd. Installation is very easy requiring only simple hand tools and a couple hours (no spring compressors required). These spacers attach to the top of the strut and will not make the ride harsh like stiffer coils or spring insert spacers can do. Using the 2" kit will also allow you to keep your downward wheel travel for a stock-like ride (again, unlike heavy lift springs that reduce down travel and make the ride extremely harsh because the wheel can no longer follow the road). Our leveling kits also come with upgraded urethane bumpstops to prevent harsh bottoming and to prevent the shock seals from getting damaged at full compression. Kit includes spacers an new cotter pins.