Fabtech 2017 Ford F450/F550 4WD Diesel 6in Front Dirt Logic 4.0 Reservoir Coilover - PassengerThe largest vehicle specific take apart monotube shock on earth. The Dirt Logic 4. 0 continues to expand its applications to include a remote reservoir style for GM and Dodge. The Dirt Logic 4. 0 will provide the ultimate in hardcore offroad dampening capacity with superior highway comfort. Nothing else comes close.