Pacbrake HP10019 Rear Air Suspension Kit The strongest air springs on the market for select Dodge, Ford*, GM & Mazda** trucks Fits with a Reese 5th wheel rail kit (Models 30033, 30035 & 30729)*** Reinforced Aluminum End Caps  Anodized for corrosion resistance 18 Support Wires & 2 Ply Rubber - For extra durability & added strength Lifetime Warranty