This tailpiece was know as the 'Frequensator' and originated in the 1940's. It was and still is used on many archtop guitars including instruments by Epiphone. The large mounting bracket is flat on the side the screw holes are drilled and includes the center 4th hole for the strap button. There are two hooks for each long and short trapeze on the opposite end of the mounting bracket to securely attach the trapeze sections where string tension holds them securely in place. The hex nuts on the threaded ends of the trapeze sections hold the string mount brackets in correct position. Mounting screws are included. Important Specs and Dimensions: Mounting Bracket Width of plate with mounting screws = 2 17/32 in. (64.3mm) Length of mounting bracket side with mounting holes = 1 39/64 in. (41mm) from end to bend Length of mounting bracket from bend to trapeze hook tops = 1 13/64 in. 30.5mm) Length of short trapeze to top of string retainer bar (not including nut heights) = 2 1/2 in. (63.35mm) Short bracket width = 1 3/64 in. (26.65mm) String Bracket width = 1 3/16 in. (30.35mm) Length of long Trapeze section including string bracket = 6 in. (152mm) Widths of each trapeze and string bracket are equal