CARBON EXPRESS D-STROYER PILEDRIVER ARROWS 400 6 PK. Adding some weight to the line the D-Stroyer Pile Driver is the heaviest arrow in the Carbon Express line and designed to create maximum kinetic energy and deliver greater knock-down power. With patented Dual Spine weight Forward Technology this two-spine arrow shaft reduces the oscillation by half for twice the accuracy of a single spine shaft to deliver superior stabilization and exceptional broadhead flight.