$140 OBO
This is a complete set of helper springs for import or mid-size trucks. All U-bolts, brackets, washers, nuts, etc are included.
They are progressive springs that do not change the original ride of the truck. As the load increases in the truck box, the springs are activated.
Rated at medium duty for up to 1500 lbs extra capacity.
They were on my 2002 Frontier.
They will fit Nissan, Toyota and small domestic models.
See the Hellwig site for more details.