Permanent Installation Includes All Connecting Brackets And Hardware Needed To Connect One Scissor Jack To FrameMade In U.S.A.Automatically Moves Into Place When Jacks Are LoweredNo T-Handles, Twist Locks, Thumb Screws, Or Other Locking Devices NeededGreatly Reduces Side-To-Side Movement In The TrailerAttaches To All Scissor Jacks, Except BAL Low ProfileCan Be Attached From A Scissor Jack To Frame On Any One Of The Four Corners Of Trailer