Fox 2007 Chevy 1500 4WD w/UCA 2.5 Factory Series 5.35in. R/R Coilover Shock Set - Black/ZincUncompromised performance through FOXs patented internal bypass technology delivers the feel of near endless suspension travel. Exclusive internal bypass technology allows oil to flow around the piston at some points of the stroke while creating humongous pressure at other points supporting the vehicle like no other product can. Floating through terrain is accomplished with FOXs ride zone combining a race developed shock piston, internal bypass and