L.B. Foster introduces its new four anchor Model F21 and F51 Series Direct Fixation Fasteners. Model F21 features a standard DFF footprint with two additional anchor locations. Model F51 features a fully captive plate design in a lighter weight and more compact unit than the typical bonded DFF. Both stabilize vertical and lateral rail movement, control longitudinal rail movement, electrically isolate rail from the track bed and provide track noise and vibration dampening.