Incorporating the lindam u shaped pressure fit power frame for ultimate strength when in position together with a dual action opening system and secondary locking mechanism for added safety featuresdouble locking mechanismthe lindam u shaped powerframe gives solid pressure fit without the need for drilling or screwsassembled ready for usedual action opening system1 way opening at the bottom of stairs two way opening in doorways adjusts to fit openings between 76cm and 82cmanti pinch hingefull